Sunday

April 20, 2014

April 20, 2014

Number of results: 23,180

**Chem**

f the molecular mass for a chemical is 352.04 g/mol and the enthalpy of formation is -2137 kJ/mol, the heat change will be ______ kJ when 10.0 g of this chemical is formed.
*Monday, May 17, 2010 at 2:08pm by Andrew*

**Chemistry**

Chloroform (CHCL3) has a normal boiling point of 61 'C and an enthalpy of vaporization of 29.24 kJ/mol. What is the value of delta Gvap (in kJ) at 61'C for chloroform?
*Tuesday, April 30, 2013 at 1:42am by Chloe*

**Chemistry**

The logic does not follow.The statement can be true but it may not be true, also. It depends upon the reaction. Endergonic refers to the Gibbs free energy while exothermic refers ONLY to the change in enthalpy, delta H. So you are comparing apples and oranges.
*Monday, August 3, 2009 at 6:03pm by DrBob222*

**chemistry**

The enthalpy of neutralization for the reaction of a strong acid with a strong base is -56 kJ/mol of water produced. How much energy will be released when 185.0 mL of 0.400 M HCl is mixed with 152.5 mL of 0.500 M NaOH?
*Sunday, November 13, 2011 at 4:00pm by Bill *

**Chemistry**

Experience told me the answer. Lacking that you might be able to find a table that will tell you. See if you text has one on heat of solution or enthalpy of solution. Here is a partial table I found on the web. (Broken Link Removed)
*Wednesday, May 2, 2012 at 8:27pm by DrBob222*

**Physics**

A motorboat is traveling 5m/s East, and encounters a current traveling 2.5m/s, North. If the witdth of the river is 80m wide, how much time does it take the boat to reach the other shore. I understand how to calculate the resulatant velocity, but I dont understand why you use ...
*Wednesday, October 20, 2010 at 2:38pm by Jennifer *

**math**

Consider the function defined below. y = 2t3 - 4t2 + 3 (a) Calculate the second derivative. y '' = (b) Calculate the third derivative. y ''' =
*Monday, June 21, 2010 at 10:48pm by Jack*

**Math**

Although you could calculate the velocity for the return, there is no information to calculate the velocity for the trip from the nest. How fast did the plane fly?
*Thursday, June 30, 2011 at 5:14pm by PsyDAG*

**Chemistry **

Calculate the wavelength of broadcast waves. Calculate the energy associated with the broadcast frequency for WPHT, 1210 kHz.
*Saturday, November 5, 2011 at 10:14pm by Anonymous*

**Chemistry**

You can calculate Keq as follows: dGrxn = (n*dGoproducts) - (n*dGoreactants) Then dG = -RT*lnK Substitute for dG, R, and T and calculate K
*Monday, November 25, 2013 at 7:23pm by DrBob222*

**Chemistry**

If the problem is to calculate the pH of the buffer, then you must have the concn of NH4NO3. Or if you were given a pH of the buffer, you can calculate the concn of NH4NO3 needed to produce that pH. You must know one of them to calculate the other.
*Friday, November 11, 2011 at 8:45pm by DrBob222*

**chem**

First calculate the energy of one photon. E = hc/lambda Then knowing the total energy you can calculate the number of photons.
*Wednesday, October 29, 2008 at 12:22pm by DrBob222*

**chemistry**

calculate [h3o] in solutions. 0.040 of HCl and 0.080 HOCl. 2. calculate OH for the solutions of 0.0063 ba (OH)2 and 0.0110 of BaCl2
*Sunday, April 11, 2010 at 7:53pm by anonymous*

**math**

calculate the mass (in SI units) of a 150ib human being? m= Calculate the weight ( in English units) of a 200kg rhino m=
*Thursday, January 26, 2012 at 4:26pm by bree*

**chemistry**

calculate r.m.s velocity of he molecule at 300k.also calculate the total k.e(in calories)of the molecules in one litre he at 300k & 1atm?
*Friday, July 6, 2012 at 1:58am by dip*

**math**

Use the binomial distribution. If you calculate by hand, here is a formula: P(x) = (nCx)(p^x)[q^(n-x)] x = 0 n = 2 p = .5 q = 1 - p = .5 Substitute into the formula and calculate. I hope this will help.
*Thursday, November 1, 2012 at 8:29pm by MathGuru*

**physics**

Calculate upstream rate = d/t. Calculate downstream rate = d/t. subtract rates to obtain speed of the river.
*Thursday, October 4, 2007 at 12:10pm by DrBob222*

**Math calculate depreciation**

please explian how to calculate depreciation for federal income taxes what method do I use thanks :)
*Wednesday, November 14, 2007 at 12:55pm by Anonymous*

**Physics**

calculate the charge of 1.56E20 electrons, you know the charge on each electron. then calculate time, knowing q .05t=ln (q/2)
*Saturday, February 5, 2011 at 11:59am by bobpursley*

**Chemistry-Help**

An AM radio station broadcasts at 1060 kHz. Calculate the wavelength of the corresponding radio waves. How do I calculate this?
*Monday, April 30, 2012 at 12:01pm by Liz*

**algebra functions**

how do i calculate this if f(x)= 3x+1 and g(x)=x+2 find (fg)(x)and calculate (fg)(2) is this multiplication and if so what do i do first any help would be appreciated
*Sunday, October 20, 2013 at 5:32pm by christin*

**Physics**

A worker applies a constant force of magnitude F = 339 N on a crate in a direction è = 26.1o above the horizontal as he pulls it across a level floor through a distance of s = 7.20 m. The mass of the crate is m = 53 kg and the coefficient of kinetic friction between the floor ...
*Tuesday, December 18, 2012 at 7:03pm by Sara H*

**Chemistry**

20cm3 of 0.500moldm-3 H2SO4 was consumed to neutralize 50cm3 of 0.400moldm-3 NaOH. The temperature of the system is increased by 36 degree C. The heat capacity of the calorie meter was 39 JK-1, and the heat capacityof the solution is 4.2JK-1. Find the enthalpy of ...
*Thursday, February 21, 2013 at 2:44am by Emma*

**Chemistry**

20cm3 of 0.500moldm-3 H2SO4 was consumed to neutralize 50cm3 of 0.400moldm-3 NaOH. The temperature of the system is increased by 36 degree C. The heat capacity of the calorie meter was 39 JK-1, and the heat capacityof the solution is 4.2JK-1. Find the enthalpy of ...
*Thursday, February 21, 2013 at 2:44am by Emma*

**Chemistry**

20cm3 of 0.500moldm-3 H2SO4 was consumed to neutralize 50cm3 of 0.400moldm-3 NaOH. The temperature of the system is increased by 36 degree C. The heat capacity of the calorie meter was 39 JK-1, and the heat capacityof the solution is 4.2JK-1. Find the enthalpy of ...
*Thursday, February 21, 2013 at 5:13am by Emma*

**Maths**

The distance from TDC (top dead centre) for the pin is given by x when the crank is at angle . Hence : i) Give an equation for x in terms of the other variables (r, L and ). ii) If the crank rod is rotating at a constant value of ω calculate the speed of ...
*Tuesday, May 17, 2011 at 7:18am by Karl Haxell*

**math**

The distance from TDC (top dead centre) for the pin is given by x when the crank is at angle . Hence : i) Give an equation for x in terms of the other variables (r, L and ). ii) If the crank rod is rotating at a constant value of ω calculate the speed of ...
*Tuesday, May 17, 2011 at 3:16pm by Karl Haxell*

**Chemistry(Please help)**

Yes it just says calculate the vp of the solution when aspirin is dissolved in the CHCl3. So then I do not have to calculate the moles/total moles?
*Sunday, February 19, 2012 at 4:16pm by Hannah*

**AP Chem**

Sure it does. But you must calculate and give what the problem asks you to calculate. mols H2SO4 = 0.054/0.667 L = ? mols H^+ = twice that.
*Sunday, April 1, 2012 at 8:39pm by DrBob222*

**Physics**

A 275 kg piano slides 4.0 m down a 30° incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. The effective coefficient of kinetic friction is 0.40. a) Calculate the magnitude of the force exerted by the man. b) Calculate the work ...
*Wednesday, December 11, 2013 at 9:01pm by Josh*

**Physics**

A 275 kg piano slides 4.0 m down a 30° incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. The effective coefficient of kinetic friction is 0.40. a) Calculate the magnitude of the force exerted by the man. b) Calculate the work ...
*Wednesday, December 11, 2013 at 9:02pm by Josh*

**chemistry**

an organic sbstance has an enthalpy of vaporization of 29.0 kl/mol. the compound has a vapor pressure of524 mm HG at 25 C. at what tempurture is the vapor pressure equal to 115mm HG?
*Saturday, June 12, 2010 at 1:11pm by nancy*

**science**

The enthalpy of solution of KBr in water is about +198 kJ/mol. Nevertheless, the solubility of KBr in water is relatively high. Why does the solution process occur even though it is endothermic
*Thursday, January 17, 2013 at 4:48pm by Samantha*

**CHEM LAB**

What is the Molar Enthalpy of Neutralization in kJ/mol if 5.00 moles of HCl(aq) (acid) neutralized 5.00 moles of NaOH(aq) (base) and released 6649J of heat?
*Tuesday, November 5, 2013 at 5:52pm by BRANDIE*

**chemistry**

What is the Molar Enthalpy of Neutralization (ÄHn) in kJ/mol if 5.00 moles of HCl(aq) (acid) neutralized 5.00 moles of NaOH(aq) (base) and released 2033 J of heat?
*Sunday, November 17, 2013 at 3:28pm by brittany sheats*

**science **

What is the Molar Enthalpy of Neutralization (ÄHn) in kJ/mol if 5.00 moles of HCl(aq) (acid) neutralized 5.00 moles of NaOH(aq) (base) and released 2033 J of heat?
*Sunday, November 17, 2013 at 3:31pm by brittany sheats*

**Physical Science**

How do you calculate the mass and volume of an irregular solid object and calculate the density of that object?
*Sunday, January 25, 2009 at 8:05pm by Alex*

**chemistry**

% recovery: how do i calculate it? we're doing a recrystallization in chem class we used 0.1 g and we recovered 0.3 g how do i calculate the percent recovery?
*Wednesday, February 9, 2011 at 6:43pm by jessie*

**calculate ratios**

Calculate the amount of drug in a ratio solution. How many micrograms are in 1ml of a 1:5000 solution?
*Tuesday, March 6, 2012 at 12:52pm by Vicki*

**physics**

U = potential energy of spring = (1/2) k x^2 calculate U for x = .244 meter calculate U for x = .122 meter decrease in U = (1/2) m v^2
*Monday, February 24, 2014 at 8:34pm by Damon*

**Maths**

In an orthonormal system, you're given the following: Point P(1,2) Lina a=cartesian eqn:4x-3y+6=0 Line b=parametric eqns:x=-5+3& y=-& (real n°) Circle z=cartesian eqn:x²+y²-2x-3=0 (a)Calculate the angle between lines a an b (b)Calculate the coordinates of the point of ...
*Sunday, May 4, 2008 at 4:14pm by Anonymous*

**Mathematics**

In an orthonormal system, you're given the following: Point P(1,2) Lina a=cartesian eqn:4x-3y+6=0 Line b=parametric eqns:x=-5+3& y=-& (real n°) Circle z=cartesian eqn:x²+y²-2x-3=0 (a)Calculate the angle between lines a an b (b)Calculate the coordinates of the point of ...
*Sunday, May 18, 2008 at 9:14am by Anonymous*

**Biophysical Chemistry**

The combustion of 1 mole of C2H5OH (Ethanol) in a bomb calorimeter produces 1364 kJ/mol at 25 degree Calcium. What is the value of enthalpy chamge for the following combustion reaction? C2H5OH(l) + 3O2(g) => 2CO2(g) + 3H2O(l)
*Tuesday, December 21, 2010 at 8:33pm by Laura *

**CHEMISTRY**

The enthalpy of neutralization for the reaction of a strong acid with a strong base is −56 kJ/mol of water produced. How much energy will be released when 198.5 mL of 0.400 M HCl is mixed with 150.1 mL of 0.500 M NaOH?
*Tuesday, May 1, 2012 at 1:22am by Sarah*

**CHEMISTRY**

The enthalpy of neutralization for the reaction of a strong acid with a strong base is −56 kJ/mol of water produced. How much energy will be released when 200.5 mL of 0.400 M HCl is mixed with 149.1 mL of 0.500 M NaOH?
*Tuesday, October 9, 2012 at 11:15pm by Sarah*

**physics**

Calculate the time it takes to travel 85 m. That is just 0.45 s. Then, calculate how much the bullet falls in that time. Use Y = (g/2)t^2 That will be the miss distance.
*Tuesday, November 23, 2010 at 7:29pm by drwls*

**chemistry**

The electron in a hydrogen atom is excited and makes a transition from n=2 to n=7 a. calculate the energy of the photon absorbed in joules. b. calculate the wavelength of the photon in meters HOW DO I DO THIS?
*Monday, March 21, 2011 at 12:08am by Tina*

**Chemistry**

Calculate how much heat 32.0 g of water absorbs when it is heated from 26.0°C to 73.5°C. In joules, and then we have to calculate calories too, how is that done? I was absent. Thanks so much!
*Wednesday, May 25, 2011 at 6:19pm by Jane*

**Chemistry**

I guess I am still stuck on problem a. I know I have to calculate Ka from Kb in order to calculate pH. When I do that, I get a pH over 14 which cannot be. What am I doing wrong?
*Monday, April 1, 2013 at 8:36pm by Jill*

**Chemistry**

I guess I am still stuck on problem a. I know I have to calculate Ka from Kb in order to calculate pH. When I do that, I get a pH over 14 which cannot be. What am I doing wrong?
*Monday, April 1, 2013 at 8:36pm by Jill*

**ap chem**

delta T = Kf*molality. Calculate molality. molality = moles/kg solvent. Calculate moles. moles = grams/molar mass. Calculate molar mass.
*Tuesday, April 13, 2010 at 11:44pm by DrBob222*

**Chemistry!**

Start from an equation 2PhMgBr + PhCOOMe -> Ph3COH so you need 2 moles of the Grignard reagent to each mole of the ester. As one mole of the PhBr formed from one mole of the Grignard reagent we need 2 moles of the PhBr. So you need to 1. calculate the molar mass of each ...
*Thursday, December 9, 2010 at 1:42am by Dr Russ*

**Chemistry**

With a platinum catalyst, ammonia will burn in oxygen to give nitric oxide, NO. 4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) ÄH = -906 kJ What is the enthalpy change for the following reaction? NO(g) + 3/2 H2O(g) NH3(g) + 5/4 O2(g)
*Saturday, October 18, 2008 at 10:36pm by Glenna*

**Chem Lab**

What is the Molar Enthalpy of Neutralization (ÄHn) in kJ/mol if 5.00 moles of HCl(aq) (acid) neutralized 5.00 moles of NaOH(aq) (base) and released 2033 J of heat?
*Sunday, November 17, 2013 at 3:27pm by brittany sheats*

**physics**

Having trouble with this one: A capacitor having a capacitance of 10uF is charged by 100v battery. A.)Calculate the charge on the capacitor? B.)calculate the energy stored in the capacitor? C.) the terminals of the capacitor is now disconnected from the batery and the ...
*Sunday, February 28, 2010 at 3:54pm by morgan*

**Chemistry**

The ΔHof of gaseous dimethyl ether (CH3OCH3) is –185.4 kJ/mol; the vapour pressure is 1.00 atm at –23.7oC and 0.526 atm at –37.8oC. a) Calculate ΔHovap of dimethyl ether. b) Calculate ΔHof of liquid dimethyl ether Any idead how to calculate for the heat of ...
*Tuesday, December 11, 2012 at 3:58pm by xavier*

**chem**

For substance A the emlting point is 16.61 degrees C and the specific heats of the solid and the liquid form are 2.662 and 5.188 JgC respectively. It requires 38600 joules to move 120g of A from 0 degrees C to 32.5 degrees C. This leads to the conclusion that the enthalpy of ...
*Sunday, February 1, 2009 at 2:40pm by Amanda*

**phys**

An airplane is heading due south at a speed of 590 km/h. If a wind begins blowing from the southwest at a speed of 65.0 km/h (average). Calculate magnitude of the plane's velocity, relative to the ground. Calculate direction of the plane's velocity, relative to the ground. ...
*Tuesday, September 15, 2009 at 4:18am by physics*

**Chemistry**

Mass (before reaction): test tube + HCl(aq) + stir bar + capsule 26.600 g Mass (after reaction): test tube + HCl(aq) + stir bar + capsule 25.300 g Volume of water displaced from the squirt bottle 148 mL Temperature of the CO2(g) 287.4 K Pressure (atm) 1.032 atm Using this data...
*Sunday, October 21, 2012 at 6:33pm by Karina*

**Chemisty**

moles = grams/molar mass. Calculate moles. m = moles/kg solvent. Calculate m delta T = Kf*m Calculate delta T. The freezing point of the solvent, normally, is 0o C. The freezing poing depression constant for the solvent, H2O, is 1.86 o/m. You may have rewritten the problem, ...
*Sunday, March 7, 2010 at 7:37pm by DrBob222*

**thermal physics**

can u tell me how to calculate kinetic energy? formula is 3RT/2(avogadro no.)=3kT/2. BUT to calculate per atom instead of avogadro no I should place 1?
*Thursday, April 9, 2009 at 5:26am by nirali*

**Climatology**

You and I differ on the term measurement. Computers simulate and calculate, not measure (IMO). If the baseline is 1990, you start there. Then, calculate it from 1990 to 2050 (when the problem asked for it).
*Thursday, May 21, 2009 at 5:13pm by bobpursley*

**Physics please help!**

h/mv = L m v = h/L v = h/(m L) calculate v - make sure <<3*10^8 calculate (1/2) m v^2
*Sunday, April 22, 2012 at 8:37pm by Damon*

**chemistry**

for a .001M solution of methionine: a) calculate the isoelectric pH b) calculate the isoionic pH
*Sunday, April 7, 2013 at 7:58pm by Lana*

**PHYSICS**

I don't know where to start solving this question. Please help! A 320 kg piano slides 3.7 m down a 32 degree incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. The effective coefficient of kinetic friction is 0.39. Calculate the ...
*Monday, November 8, 2010 at 3:52am by MegP*

**Thermodynamics**

a rigid vessel of volume 1m(^3) contains steam at 20bar and 400 degrees Celcius. The vessel is cooled until the steam is just dry saturated. Calculate the mass of steam in the vessel, the final pressure of the steam and the heat rejected during the process. The answers should ...
*Friday, March 12, 2010 at 3:30am by Claire*

**chemistry**

The enthalpy of combustion of benzoic acid,C6H5COOH, which is often used to calibrate calorimeters, is -3227kJ/mol. When 1.236g of benzoic acid was burned in a calorimeter, the tempurature increased by 2.345K. What is the specific heat of the calorimeter?
*Sunday, November 2, 2008 at 11:09pm by annemarie*

**College (Enthalpy) - College**

Use equation 1 as is. Reverse equation 2 (changer sign, too) and add to equations. Add delta Hs. Cancel ions common to each side. You should have S(rhombic) ==> S(monoclinic)
*Sunday, October 31, 2010 at 7:11pm by DrBob222*

**Chem**

The brown color associated with photochemical smog is due to NO2(g). This is involved with the following equilibrium in the atmosphere: 2 NO2(g) <===> N2O4. Predict the signs of the enthalpy and entropy changes for this reaction. If the equation is at equilibrium should ...
*Sunday, March 30, 2008 at 6:25pm by Ginger*

**chem**

The complete combustion of butane, (g) is represented by the equation C4H10+ 13/2O2->4CO2+5H2O standard enthalpy is -2877kj How much heat, in kilojoules, is evolved in the complete combustion of 12.8ml at 23.8degrees celsius and 744mmhg ?
*Wednesday, October 8, 2008 at 5:06pm by tomi*

**chemistry-URGENT**

Hydrazine is used as a rocket fuel. When 1.50 g of hydrazine, N2H4, was burned in a bomb calorimeter, temperature increased from 23.57 °C to 28.84 °C. The heat capacity of the calorimeter was 5.510 kJ/°C. Determine the enthalpy of combustion of octane.
*Sunday, April 10, 2011 at 7:59pm by Maria*

**epidemiology**

In a fictitious study, 100 out of 1000 people aged 60 years and over were positive in detecting breast cancer using Tumour Biopsy (gold standard). Using mammography, 90 of breast cancer patients and 135 healthy persons were also positive by this test. (I) Calculate and ...
*Saturday, August 18, 2012 at 2:13pm by Ekrem*

**Physics**

A particle's initial velocity is given by vox = -1.0 m/s and voy = 3.0 m/s. Its acceleration is ax = 0.50 m/s^2 and ay = -0.90 m/s^2 (a) Calculate its velocity 2.0 s later. (b) Calculate its displacement at that time.
*Sunday, October 4, 2009 at 1:57pm by Sandhu*

**chemistry**

Use PV = nRT again. You know volume from the previous work, then plug in R, T, and P, calculate n for H2. Then moles = grams/molar mass will allow you to calculate grams.
*Wednesday, January 27, 2010 at 12:52am by DrBob222*

**statistics**

GIVEN THE FOLLOWING STATISTICAL VARIABLES A:m(A)=5 B:m(B)=13 var(A)=25 Var(B)=6 1.calculate mean of Z= 4B-2A 2.Calculate the Standard Deviation assuming cov (A,B)=0
*Tuesday, August 17, 2010 at 2:15am by RASHMI*

**chemistry**

Calculate the change in internal energy of the system in a process for which 100J of heat is absorbed by the system from surroundings and does 85J of work. (I want to learn the solution on how to calculate it... pls. help thank you... )
*Sunday, January 23, 2011 at 11:49am by jaycab*

**physic**

Calculate the mass (in SI units) of a 150 lb human being. m= (correct unit) Calculate the weight (in English units of a 2000 kg rhinoceros.
*Friday, January 27, 2012 at 1:31pm by sam*

**algebra**

First insert values in above equation to calculate L. Then use values to calculate Volume = L * H * W (Online "*" is used to indicate multiplication, because "x" is often confused with an unknown.)
*Wednesday, March 28, 2012 at 11:53pm by PsyDAG*

**Math (Finance)**

You have a note in the amount of $10,000 at 9.5% interest running from january 5. to april 16 a. calculate the ordinary intrest. b. calculate the exact interest.
*Wednesday, October 31, 2012 at 1:24pm by Renee*

**Chemistry **

Calculate the energy released when an electron is added to a hydrogen nucleus. Assume the transition is n= infinite to n=1. I know equation to use but how do I calculate when n is infinite and no number ?? Please some help
*Thursday, November 29, 2012 at 12:39am by Anonymous*

**Chemistry**

I-I:150 F-F:160 C-C:350 H-H:435 (a) Calculate the energy of the I-F bond. Express your answer in units of kJ/mol. unanswered (b) Calculate the % ionic character of the I-F bond.
*Tuesday, March 5, 2013 at 1:04pm by Anonymous*

**chemistry**

calculate the Ph of 0.3 M sodium propanoate, Ka 2.0 x 10 base -3. then calculate the pH after 0.03 mol NCL is added to 2L of the first solution.
*Saturday, July 20, 2013 at 1:36pm by Mandy*

**HEALTH**

The key to using a pedometer to meet the Physical Activity Guidelines for Americans is to _________. A. First set a time goal and then calculate how rigorous the steps need to be each day to reach your goal B. First calculate how many steps are needed weekly and then match it ...
*Wednesday, April 17, 2013 at 3:54pm by CARRIE*

**Chemistry**

Hi! I was studying for an exam (lol) and I came across something I don't quite understand.. could someone help me with Standard Enthalpy of Formation? The equation in my notes looks like this: ΔHºrxn = ΣΔHºf(products) - ΣΔHºf(reactants) Thanks in advance!
*Sunday, December 14, 2008 at 5:21pm by Chris*

**Chemistry**

This question isn't worded very well in my opinion but I think you want just the enthalpy for the reaction given. Those are dHrxn = (n*dH products) - (n*dH reactants) dHrxn = (1*MgCl2 + 1*H2O) - (1*MgO + 2*HCl) dHrxn = [1*(-641) + 1*(-286)] - [1*(-602) + 2*(-167)] = ?
*Thursday, January 30, 2014 at 7:40am by DrBob222*

**chemistry**

1.) For which of the following substances is the standard enthalpy of formation equal to zero? a) water [H2O(l)] d) carbon dioxide [CO2(g)] b) lead [Pb(l)] e) tin [Sn(s)] c) carbon dioxide [CO2(s)] 2.) Consider the following four equations: 1. C6H6(l) + O2(g) 6CO2(g) + 3H2O(l...
*Wednesday, August 3, 2011 at 5:51pm by tt*

**Physics**

2. Charge q1 is located at (0,+30 cm). Charge q2 is located at (0, -30 cm) q1 = +25 pC q2= -75 pC A) Calculate the potential energy of the charges B) Calculate V1, the electric potential at the orgin due to charge q1, and V2, the electric potential at the orgin due to charge ...
*Tuesday, April 12, 2011 at 12:00pm by YoungTangerine*

**college chemistry**

The enthalpy of combustion of benzoic acid,C6H5COOH, which is often used to calibrate calorimeters, is -3227kJ/mol. When 1.236g of benzoic acid was burned in a calorimeter, the tempurature increased by 2.345K. What is the specific heat of the calorimeter?
*Monday, November 3, 2008 at 5:33am by annemarie*

**chemistry**

a 3.35g sample of solid silver reacted in excess chlorine gass to give a 4.45g sample of pure solid AgCl. the heat given off was 3.95kJ at constant pressure. what is th enthalpy of formation of AgCl?
*Monday, June 21, 2010 at 11:11am by Ellie*

**chemistry**

Hi, The problem is: "Calculate the concentration of OH- and the pH value of an aqueous solution in which [H30+] is 0.014M at 25C. Is this solution acidic, basic, or neutral?" I have calculated the OH- concentration to be: 7.1 X 10^-14 When I calculate the pH (using H30+), I ...
*Wednesday, March 30, 2011 at 2:54pm by LaurenM*

**Chemistry (Enthalpy)-College**

Use equation 1 as is. Reverse equation 2 (change the sign) and add to equation 1. Add the delta Hs to arrive at the total delta H for the new reaction.
*Sunday, October 31, 2010 at 7:10pm by DrBob222*

**Chemistry**

delta T = Kb*molality. Step 1. Calculate molality from the above. Step 2. Remember that molality = # mols/kg solvent. Calculate # mols from that. Step 3. Use # mols = g/molar mass to calculate molar mass. Post your work if you get stuck.
*Monday, October 27, 2008 at 6:15pm by DrBob222*

**Chemistry using concentration**

Then you didn't read it very carefully. I'll draw you a picture. mols NaOH = grams/molar mass You have grams NaOH of 1.852. You can get molar mass NaOH. Calculate mols NaOH. Calculate mols NaOH needed.The above does that calculation for you but you must plug in the numbers and...
*Monday, May 12, 2008 at 12:37am by DrBob222*

**chemistry**

A studen is asket to calculate the amount of heat involved in changing 10.0 g of liquid bomine at room temperature (22.5 C) to vapor at 59.0 C. To do this, one must know specific heat (0.474 J/g*C), boiling point (59 C), and heat of vaporization (29.6 kJ/mol) of bromine.In ...
*Wednesday, March 30, 2011 at 8:52pm by Lena*

**chemistry - quant.**

I need help calculating the pH of a solution that is .0400M Na3AsO4 I was trying to calculate the pH with [H30+]=sqrt(ka1*ka2) What is the correct way to calculate this? Thankyou
*Thursday, December 13, 2007 at 12:28pm by anon*

**Science**

1. Write and balance the equation. 2. Calculate moles of HCl and moles Mg(OH)2, determine which will react completely and which will remain, then calculate pH from that data. Post your work if you get stuck.
*Tuesday, April 13, 2010 at 7:31pm by DrBob222*

**physics**

If all they are asking for is the initial KE, then all you have to do is calculate (1/2)MV^2 = (0.5)(1.15)[(-.46)^2 + (.36)^2] = 0.196 J The applied force will allow you to calculate the velocity at later times, but they are not asking for that.
*Monday, November 22, 2010 at 8:38pm by drwls*

**physics**

A force of 303.0 N is used to push a 160 kg mass 30.0 m horizontally in 3.00 s. (a) Calculate the work done on the mass. 1 kJ (b) Calculate the power developed. 2 kW
*Monday, December 12, 2011 at 12:42am by Anonymous*

**Chemistry**

I don't think that you need the equation- just calculate the moles in 3.0ml of a 3.0M solution of HCl and then calculate the mass needed from the number of moles for molecular weight of NaHCO3.
*Wednesday, February 27, 2013 at 9:34pm by Devron*

**Chemistry **

How would I calculate this? I have the answer because its from a previous test I just want to know how I would calculate it. How many grams of NaCI are contained in 350. mL of a 0.133 M solution of sodium chloride?
*Sunday, June 30, 2013 at 9:10am by Mary *

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