Monday
August 29, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
How many grams of O2 are there in a 50.0L tank at 21*C when the pressure is 1.19x10^4mmHg?
Tuesday, July 19, 2016 by Brooke

Chemistry
The human body obtains 885 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize at 100 degree Celsius, how many grams of water could be vaporized? The heat of vaporization of water at 100 degrees Celsius is 40.7 kJ/mole.
Tuesday, July 19, 2016 by Jane

Chemistry
At constant pressure , a certain gas occupies 80cm3 at 0 degrees, what wil be its volumd at 10 degrees
Tuesday, July 19, 2016 by Max

chemistry
what happens to water at 100 degrees celsius as pressure is increased fro 0.8 atm to 1.2 atm?
Tuesday, July 19, 2016 by barb

Chemistry
The boiling point of alcohol is 78.3 degrees Celcius at 760 mm atm pressure. Would the boiling point be higher or lower than 78.3 degree Celcius at hugher altirudes? Why?
Tuesday, July 19, 2016 by Chen

Chemistry
If 30ml of the standard sodium edetate soln neutralized 25ml of solution containing 0.25g of dried magnesium sulphate. Calculate the %w/v of mgso4 in the dried mgso4
Tuesday, July 19, 2016 by Kingsley Ekpe

CHEMISTRY
A compound which contains hydrogen, oxygen, carbon only has molar mass of about 85 g/mol. When 0.43 g of the compound is burned in excess of oxyfen, 1.10 g of CO2 and 0.45 g of H2O are formed. Find the molecular formula and the empirical formula of the compound
Monday, July 18, 2016 by Clive Lodnyx

chemistry
Hydrogen chloride reacts with water to produce an ion with the chemical formula H3O+. An H3O+ ion has one dative covalent bond. Explain how the bond is formed.
Monday, July 18, 2016 by Rose

Chemistry
For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate...? For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate. (Begin by writing a chemical...
Monday, July 18, 2016 by Juliet

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of Na2O completely reacts. Assume that there is more than enough of the other reactant. Na2O(s)+H2O(l)→2NaOH(aq)
Sunday, July 17, 2016 by Javier

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of Mg completely reacts. Assume that there is more than enough of the other reactant. 2Mg(s)+O2(g)→2MgO(s)
Sunday, July 17, 2016 by Leo

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of CaO completely reacts. Assume that there is more than enough of the other reactant. CaO(s)+CO2(g)→CaCO3(s)
Sunday, July 17, 2016 by Rachel

Chemistry
For the reaction shown, calculate how many grams of oxygen form when each of the following completely reacts. 2HgO(s)→2Hg(l)+O2(g)
Sunday, July 17, 2016 by Marley

chemistry
what is the precipitate form of 2naoh+cuso4->na2so4+cu(oh)2
Sunday, July 17, 2016 by charshley

Chemistry
A CaCl2 solution is given to increase blood levels of calcium. If a patient receives 5.0 mL of a 5.0 % (m/v) CaCl2 solution, how many grams of CaCl2 were given?
Sunday, July 17, 2016 by Ava

Chemistry
A typical antacid contains CaCO3. If such an antacid is added to 25.0 mL of a solution that is 0.250 M in HCl, how many grams of CO2 gas are produced?
Sunday, July 17, 2016 by Maria

Chemistry
A patient received 5.0 g of NaCl in 8 hours. How many milliliters of a 0.40 % (m/v) NaCl (saline) solution were delivered?
Sunday, July 17, 2016 by maria

chemistry
what will be formed when oxygen combines with hydrogen in the presence of hydrated iron 3 oxide?
Sunday, July 17, 2016 by stephen

chemistry
Calculate the grams or milliliters of solute needed to prepare the following solutions. 1.)75. g of a 7.0 % (m/m) KCl solution 2.) 1250 mL of a 8.0 % (m/v) NH4Cl solution 3.) 270. mL of a 15.0 % (v/v) acetic acid solution I really just need to know how to work the first ...
Sunday, July 17, 2016 by maria

chemistry
Solubility (g/100gH2O) Substance 20∘C 50∘C KCl 34.0 42.6 NaNO3 88.0 114.0 C12H22O11 (sugar) 203.9 260.4 Using the above table, determine whether each of the following solutions will be saturated or unsaturated at 50 ∘C. 1.) Adding 19.7 g KCl to 35.0 g H2O 2.)...
Sunday, July 17, 2016 by maria

chemistry
a 51.6 litre sample of a pure allotrope of oxygen has a mass of 100.0 grams. (25 degrees celsius and 100 kPa) Show, by calculation, which allotrope of oxygen is present.
Sunday, July 17, 2016 by Anonymous

Chemistry
Write a balanced equation for the complete oxidation reaction that occurs when ethanol (C2H5OH) burns in air.
Sunday, July 17, 2016 by anonymous

Chemistry
0.110 M in formic acid and 5.5×10−2 M in hypochlorous acid . How to find pH
Saturday, July 16, 2016 by Sandov

Chemistry
Marcela dissolves 80.0 g of ammonium nitrate in 50.0 mL of water at room temperature and notes that the temperature of the solution decreases by 5.0°C. Which correctly designates the signs of changes of G, S and H for this reaction?
Saturday, July 16, 2016 by Damon

chemistry
Which is the more stable electron: that in a ground-state H atom or that in a ground-state He+ ion? Explain your choice.
Saturday, July 16, 2016 by ben10

chemistry
what is activation energy?
Saturday, July 16, 2016 by pat

Chemistry HELP!!!
Which of the following contains the greatest number of particles? A) 4g of helium gas B) 4g of oxygen gas C) 4g of hydrogen gas D) 4g of water Why is the answer C? Pls explain to me clearly, thks!
Saturday, July 16, 2016 by Cheezel Lim

chemistry
a given sample of MgCl2 solution has 6×10^23 ions. what is the number of Cl(-1) ions in the same solution?
Saturday, July 16, 2016 by hassan

Chemistry
A small section of a polymer chain, containing 10 repeating units, has a relative molecular mass of 625. Which of the following monomers could have polymerised to form this chain? ethylene viyl chloride styrene glucose
Saturday, July 16, 2016 by Anonymous

Chemistry
Hi, I've been working for nearly 2 hrs on this problem, but I'm stuck on the next step. Thanks for any pointers in the right direction. My problem is: How many grams of S8 are needed to produce 225 grams of sulfur hexafluoride? I was given this formula: S8+24F2(Arrow)...
Friday, July 15, 2016 by Amanda

Chemistry
How many grams of S8 are needed to produce 225 grams of sulfur hexafluoride? I know to begin with a balanced equation S8+24F2(arrow)8SF6. I've spent a couple of hours trying to figure out the next step, but I'm stuck. Thanks for any pointers!
Friday, July 15, 2016 by Darius

chemistry
What volume of 0.10 M NaOH can be prepared from 250. mL of 0.30 M NaOH? A) 0.075 L B) 0.25 L C) 0.75 L D) 0.083 L E) 750 L
Friday, July 15, 2016 by maria

Chemistry
What volume of nitric dioxied at s.t.p from the below equestion N2+O2=2NO
Friday, July 15, 2016 by Shukulu

Chemistry (DUE TONIGHT)
A possible reaction for converting methanol to ethanol is: CO(g) + 2H2(g) + CH3OH(g) -----> C2H5OH(g) + H2O(g) I completed parts A-C correctly, and found the following info: delta H = -165.6 kJ delta S = -227.4 J/K delta G = -97.9 kJ The next question is asking to estimate ...
Friday, July 15, 2016 by LC

chemistry practical
Why? alkaline solution didn't puppet out.
Friday, July 15, 2016 by Vishal Hood

chemistry
Calculate the no. Of moles of co2 is liberated gives50gm of caco3 reacts with 7.3gm of dil.hcl
Friday, July 15, 2016 by Siddhartha

chemistry
Discuss the structure of bonding in copper acetate?????
Friday, July 15, 2016 by prakash

college chemistry
prepare 0.2M phospate buffer of pH 5.7
Thursday, July 14, 2016 by rajan

Chemistry
N2H4 + 2H2O2= N2 + 4H2O What are the mole ratios of hydrazine (N2H4) to hydrogen peroxide (H2O2) and hydrazine to water
Thursday, July 14, 2016 by Damon

Chemistry
In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
Thursday, July 14, 2016 by Mariah

Chemistry
1.06g of Na2CO3 is dissolved in water to make 250cm^3 solution. 10.0 cm^3 of this solution was further diluted to make 500cm^3 of 2nd solution. 25.0cm^3 of 2nd solution reacted with 28.5cm^3 of HCl. Find the concentration of HCl in mol/dm^3
Thursday, July 14, 2016 by Gary

Chemistry
Why water can be used as a solvent in paper chromatography?
Thursday, July 14, 2016 by Steph

Chemistry
Why do different substances have different Rf values ? used in chromatography.
Thursday, July 14, 2016 by Stephenie

pharmaceutical physical chemistry
find the density of NH3 gas at 100celsius when confined by a pressure of 1600mmHg
Thursday, July 14, 2016 by gladiza

Chemistry
The reaction 2NO (g) + 2H2 -> N2 (g) + 2H2O (g) was found to follow the rate law, rate = k[NO]^2[H2]. By what factor will the rate of reaction increase when the pressure of NO gas is increased from 2.0 atm to 3.0 atm? Assume all other conditions are held constant. I'm ...
Wednesday, July 13, 2016 by Mikey

chemistry
How much heat is produced by the complete combustion of 287 g of CH4? CH4(g)+2O2(g)→CO2(g)+2H2O(g)Δ​H∘rxn=−802.3kJ
Wednesday, July 13, 2016 by Anonymous

Chemistry
How many molecules are in 5.2L of carbon dioxide gas?
Wednesday, July 13, 2016 by Joey

Chemistry
What is the test for ammonium formed on hubber process? i need your help
Wednesday, July 13, 2016 by RONALD KAZEYA

Chemistry
hydrogen sulfide reacts with sulphur dioxide to give water and S, balance the equation. if hydrogen sulfide contains 125g, how much S is produced?
Wednesday, July 13, 2016 by Love

Chemistry
hydrogen sulfide reacts with sulphur dioxide to give water and S, balance the equation. if hydrogen sulfide contains 125g, how much S is produced?
Wednesday, July 13, 2016 by Love

Chemistry
If you are asked to make exactly 1.0 Liter of 0.80 M ZnCl2 solution, how many grams of zinc chloride would you need to be massed out? How do I go about solving this problem?
Wednesday, July 13, 2016 by Annie

Chemistry
All the following are necessary parts of a neutralization reaction except A) an acid B) an indicator C) water D) a salt.
Tuesday, July 12, 2016 by Mariah

Chemistry
4.80 dm^3 of chlorine gas was reacted with NaOH solution. a) how many moles of Cl2 reacted b) what mass of NaOCl was formed? c) if the concentration of the NaOH was 2.00 mol/dm^3. What volume of sodium hydroxide solution was required? d) write an ionic equation for this reaction
Tuesday, July 12, 2016 by Gary

Chemistry
Theoretically how many grams of malachite should be formed when 1.5 moles of Copper Sulphate reacts with an excess of sodium carbonate?
Tuesday, July 12, 2016 by Dee

12th grade chemistry
It is required to titrate ethanol solution .Being available a 0.2mol/l potassium dichromate solution and 4mol/l sulfuric acid solution on the presence of a convenient indicator. a)indicate the glassware used for titration. b)give a brief description of the procedure followed ....
Tuesday, July 12, 2016 by andy

chemistry
Two compounds of molecular formula respectively C2H4O and C4H8O produce a yellow orange precipitate by the reaction DNPH. a)is this indication sufficient to write the structural formulas of these two compounds? Explain. b)what identification tests should further be done to ...
Tuesday, July 12, 2016 by angy

chemistry
How many grams of Mg(OH)2 would be produced from 4 mol KOH? if the balanced reaction is MgCl2 +2KOH arrow Mg(OH)2 + 2KCl?
Tuesday, July 12, 2016 by barb

Chemistry
Equation of Mg(OH)2 (aq) + KOH (aq) gives you what ?
Monday, July 11, 2016 by Chris

Chemistry
A student dilutes a solution so that its pH changes from 2.4 to 4.4. 10mL of the original solution was diluted by how many mL?
Monday, July 11, 2016 by Anthony

Chemistry
14 grams of coal undergoes complete combustion in 58 grams of oxygen gas. What volume of gas (measured at 25 degrees celsius and 100 kPa) is present when the reaction is complete?
Monday, July 11, 2016 by James

Chemistry
I may need this broken down step by step to understand this problem thanks. A 20.0% by mass solution of phosphoric acid (H3PO4) in water has a density of 1.114 g/ml at 20℃. What is the molarity of the solution?
Monday, July 11, 2016 by Andrew J. DuBois

Chemistry
If a current of 3.00 A is applied to a cell containing a 400g copper anode, determine the final mass of the copper anode after the cell runs for 48.0h
Monday, July 11, 2016 by Luke

Chemistry
If a solid state lithium battery produced 5.00 mA in 8.25 h, then the mass, in milligrams, of lithium consumed would be?
Monday, July 11, 2016 by Luke

chemistry
QUESTION 11 Ammonia gas is formed from nitrogen gas and hydrogen gas, according to the following equation: N2 (g) + 3H2 (g) Imported Asset 2NH3 (g). If 84.0 g of nitrogen gas is allowed to react with an excess of hydrogen gas to produce 85.0 g of ammonia, what is the percent ...
Monday, July 11, 2016 by Anonymous

chemistry
QUESTION 10 Ammonia gas is formed from nitrogen gas and hydrogen gas according to the following equation: N2 (g) + 3H2 (g) Imported Asset 2NH3 (g). If 112 grams of nitrogen gas is allowed to react with an excess of hydrogen gas to produce 120 grams of ammonia, what is the ...
Monday, July 11, 2016 by Anonymous

chemistry
QUESTION 9 The number of moles of the reagent in excess can be used to calculate the moles of the products of the reaction. TRUE FALSE
Monday, July 11, 2016 by Anonymous

chemistry
When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) Imported Asset MgCl2 (aq) + H2 (g), if 72.9 g of Mg and 146.0 g of HCl are allowed to ...
Monday, July 11, 2016 by Anonymous

chemistry
When 4.2g of NaHCO3 is added to a solution of CH3COOH Weighing 10g, it is observed that 2.2g of co2 is realised into the atmosphere . The residue left is found to be 12g . Show that this observations are in agreement with the law of conservation of mass?
Monday, July 11, 2016 by sid

chemistry
20g of NaHCO3 Treated with 22g of HCl Producing 12g of the residue. What is the amount of co2 Formed ?
Monday, July 11, 2016 by sid

chemistry
When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) Imported Asset MgCl2 (aq) + H2 (g), if 72.9 g of Mg and 146.0 g of HCl are allowed to ...
Monday, July 11, 2016 by Anonymous

chemistry
If chlorine and fluorine react according to the reaction (to balance): Cl2+ F2→ ClF3 And calculate the amount of product and of limiting reagent that remains, when 10 g of chlorine and 30 g of fluorine are reacted to give chlorine trifluoride.
Monday, July 11, 2016 by Anonymous

chemistry
For combustion of 10 grams of C4H10 excess of O2, You are obtained 25 grams of CO2 according to the reaction (to balance): C4H10+ O2→ CO2+ H2O Calculate the reaction yield of the reaction. please,could anyone help me to solve this problem.
Monday, July 11, 2016 by Anonymous

chemistry
In the gaseous phase PCl5 dissociates according to the following equilibrium: PCl5⇌PCl3+Cl2 and Kc=0.8 at 613K .Determine the equilibrium composition when 0.12 moles/L of the three compounds are mixed at 613K.
Sunday, July 10, 2016 by Anonymous

chemistry
100 mL of 0.05 M NH3 solution are added to 60 mL of a 0.1 M solution of the same compound.Determine the concentration of the final solution.
Sunday, July 10, 2016 by Anonymous

Chemistry
A 1.00 g sample of limestone is allowed to react with 100 cm^3 of 0.200 mol/dm^3 HCl. The excess acid required 24.8 cm^3 of 0.100 mol/dm^3 NaOH solution. Calculate the percentage of calcium carbonate in the limestone
Sunday, July 10, 2016 by Gary

Chemistry
Given the following three electron configurations: 1s2 2s2 2p5 How many core electrons does this element have? A. 4 B. 5 C. 9 D. 2
Sunday, July 10, 2016 by Megan

Chemistry
Which of the following atoms would have the highest first ionization energy? A. Li B. Be C. Na D. Mg
Sunday, July 10, 2016 by Megan

CHEMISTRY
A solution of a metal carbonate M2CO3, was prepared by dissolving 7.46 g of the anhydrous solid in water to give 1000cm^3 of solution. 25.0cm^3 of this solution reacted with 27.0cm^3 of 0.100 mol/dm^3 hydrochloric acid. Calculate the relative formula mass of M2CO3 and hence ...
Saturday, July 9, 2016 by DAVID

CHEMISTRY
A 1.575 g sample of ethanedioic acid crystals, H2C2O4. xH20 was dissolved in water and made up to 250cm^3 . One mole of the acid reacts with two moles of NaOH. In a titration, 25.0 cm^3 of this solution of acid reacted with exactly 15.6 cm^3 of 0.160 mol/ dm^3 NaOH. Calculate ...
Saturday, July 9, 2016 by Jack

chemistry
the standard enthalpy of formation, for HCOOH(l)is equal to the standard enthalpy for which reaction?
Saturday, July 9, 2016 by Achan

Chemistry
What is theoretical yield in grams of CO2 formed from reaction of 3.12g CS2 and 1.88g O2?
Friday, July 8, 2016 by Mariah

Chemistry
How many mol of hydrogen present in 16g methane
Friday, July 8, 2016 by Anonymous

Chemistry
Two closed vessels of equal volume both with pressure p1 and temperature t1 are connected to each other by tube with negligible volume. If the temperature maintained of both vessels is then changed to t1 and t2 respectively what is the pressure in the vessels?
Thursday, July 7, 2016 by Yuktee

chemistry
To 100 mL of a 0.1M NH3(Kb=1.8*10-5)solution,200mL of a 0.1M NaOH have been obtained.Calculate the pH of the solution.
Thursday, July 7, 2016 by Anonymous

science,physics,chemistry
According to our theory atomic size should increase in groups from top to bottom but in group 13 Aluminium has atomic radius 143 pm and Gallium has atomic radius 135 pm which is less WHY??????
Thursday, July 7, 2016 by Neh

Chemistry
What is the name for the following coordination compound or ion? Na3[Cr (NH3) NO2 Cl3]
Wednesday, July 6, 2016 by Katrina

Chemistry
In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
Wednesday, July 6, 2016 by Kelly

chemistry
What is the difference between the acid and base notation of a hydroxide? Give an example of the same molecular formula written in acid and base notation.
Wednesday, July 6, 2016 by chris

Chemistry
The specific heat capacity of copper is 0.09 cal/g°C. How much energy is needed to flow into a 10-gram sample to change its temperature from 20°C to 21°C?
Wednesday, July 6, 2016 by Mariah

chemistry
How many grams of dipotassium succinate trihydrate (K2C4H4O4·3H2O, MW = 248.32 g/mol) must be added to 790.0 mL of a 0.0522 M succinic acid solution to produce a pH of 5.872? Succinic acid has pKa values of 4.207 (pKa1) and 5.636 (pKa2). is the pH of the current ...
Wednesday, July 6, 2016 by Melodie

Chemistry
For the following reaction, identify the substance being oxidized and reduced CH4 + 2 O2 = CO2 + 2 H2O
Wednesday, July 6, 2016 by Dylan

chemistry
How many g of H2 is formed from 2.4 g H20 according to the following reaction. 2H2O--->2H2O+O2 I believe the answer is .27g However, I can't understand how to work the problem completely out or one like it, if someone could please explain the formula it would be ...
Wednesday, July 6, 2016 by me

Chemistry
For the following reaction, how many kJ of heat are produceed in forming 225.0 g of NO? 4 NH3 + 5 O2 → 4 NO + 6 H2O ΔHrxn = -906 kJ/mole
Wednesday, July 6, 2016 by Morgan

Chemistry
If the ΔH for H2O(l) → H2O(s) is -6.01 kJ, then what is the ΔH for 2H2O(s) → 2H2O(l)? A -6.01 kJ B. 6.01 kJ C. -12.02 kJ D. 12.02 kJ
Wednesday, July 6, 2016 by Leanne

Chemistry
What is the oxidized substance in the following reaction? Fe + 2HCl → FeCl2 + H2
Wednesday, July 6, 2016 by Dylan

AP Chemistry
Q - An electrochemical reaction occurs between an unknown element and zinc. The half-cell reaction for the zinc is: Zn(s) → Zn2+(aq) + 2e− The cell potential for the reaction is Eºcell = 1.83 V. Is the reaction spontaneous or nonspontaneous? Explain. What is ...
Wednesday, July 6, 2016 by Jessica AP Chemistry

AP Chemistry
Q - Aluminum metal reacts with zinc(II) ion in an aqueous solution by the following half-cell reactions: Al(s) → Al3+(aq) + 3e− Zn2+(aq) + 2e− → Zn(s) Predict the potential of the cell under standard conditions. Predict whether the reaction will occur ...
Wednesday, July 6, 2016 by Jessica AP Chemistry

AP Chemistry
Sodium can be extracted by heating naturally occurring salt until it is molten. An electrochemical process is then used to extract the sodium. Cl2 is produced at the anode, and Na is collected at the cathode. Write the half-reactions that occur at the anode and the cathode. ...
Wednesday, July 6, 2016 by Jessica AP Chemistry

Analytical Chemistry
What volume, in liters, of 1.09 M KOH solution should be added to a 0.102 L solution containing 9.35 g of glutamic acid hydrochloride (Glu, FW = 183.59 g/mol; pKa1 = 2.23, pKa2 = 4.42, pKa3 = 9.95) to get to pH 10.26? Should I start with molar concentrations in the beginning (...
Tuesday, July 5, 2016 by R

Chemistry
What volume of each of the following bases will react completely with 25.00 mL of 0.200 M HCl? a) 0.100 M NaOH b)0.0500 M Sr(OH)2 c)0.250 M KOH please explain and show detail I'm so lost on this problem... thanks!
Tuesday, July 5, 2016 by Chantelle

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Homework Help: Science