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April 18, 2014

Search: substance

Number of results: 2,081

chemistry
Which of the following is true of a substance with a pH of 11.0? A. The substance is an acid. B. The substance is a base. C. The substance is neutral. D. The substance is a transition metal. I think A
Saturday, November 10, 2012 at 3:28pm by Keri

Chemistry
Suppose 1.0 mol of substance A reacts with 1.0 mol of substance B. to produce 2.0 mol of substance C. In a reaction, 2.4 mol of substance A is allowed to react with 2.1 mol of substance B. What amount in moles of substance c is produced?
Wednesday, April 1, 2009 at 10:22pm by Andrew

chemistry
Substance A and substance B react to form substance C as described by the equation: A + B ↔ C If only substance A and substance B are placed in an enclosed vessel and allowed to react what would the reaction be?
Monday, June 13, 2011 at 3:18pm by guilford technical college

PLS HELP ASAP 1 SUPER HARD & ANNOYING QUESTION
Use the diagram to answer question 13. so substance A looks like a row of three little circles on the top and bottom all organized (total six dots). substance b is all clumped together circles and is disorganized. 13. How can substance A and B be compared? Choose all that ...
Wednesday, March 12, 2014 at 1:47pm by sonamy4eva

chemisrty
When a substance changes from one phase to another, which of the following occurs? the substance loses or gains heat the average kenetic energy of the substance changes the temperature of a substance changes the molecular motion of a substance changes
Friday, November 16, 2012 at 11:14am by Tasia

chemistry
An unknown substance has a mass of 17.3 . When the substance absorbs 1.557102 of heat, the temperature of the substance is raised from 25.0 to 45.0 . What is the most likely identity of the substance?
Monday, September 20, 2010 at 10:47pm by Kyle

chemistry
2. Imagine you have two beakers. Both beakers are filled with the same amount of water. The water in both beakers is the same temperature as well. You add 50 g of Substance A to the first beaker, and 50 g of Substance B to the second beaker. After stirring both beakers, there ...
Thursday, October 22, 2009 at 12:59pm by fatima

scince thanks
A chemical reaction is a change in which a substance reacts with a different substance usually to create a different substance or compound. A chemical change is a change in the chemical makeup of a substance usually ending with a different sunstance but the beginning substance...
Saturday, October 6, 2007 at 9:02pm by Michele

chemistry
An unknown substance has a mass of 28.1 g. The temperature of the substance increases by 16.3 degrees Celsius when 176 J of heat is added to the substance. What is the most likely identity of the substance? The table lists the specific heat capacities of select substances.
Sunday, January 26, 2014 at 7:56pm by bob

English
Select the answer that contains the correct punctuation for the following sentence. A diamond is the hardest natural substance it can scratch any other stone. A. The sentence is correct. B. ... substance, it can... C. ... substance; it can... D. ... substance; and, it can... I...
Wednesday, April 6, 2011 at 5:51pm by anthony

Chemistry
Do the following parameters indicate how stable a substance is? 1) Viscosity of a substance 2) Optical rotation of a substance
Sunday, April 15, 2012 at 12:52am by jean

chemistry
If you have 12 moles of a substance, how many molecules do you have of that substance? Suppose the substance has a molecular weight of 342. How many grams of that substance would you have to dissolve in a liter of water to make a 12 M solution?
Saturday, September 3, 2011 at 6:44pm by VANESSA

Chemistry
For the equation: deltaHrxn = qrxn / mol substance to calculate deltaH per mole what does the mol substance mean? Does this mean that you use the mm of the substance or if you already calculated the # of moles of a substance do you use that?
Monday, February 13, 2012 at 8:00pm by Hannah

Chemistry(Please help, thank you)
For the equation: deltaHrxn = qrxn / mol substance to calculate deltaH per mole what does the mol substance mean? Does this mean that you use the mm of the substance or if you already calculated the # of moles of a substance do you use that?
Monday, February 13, 2012 at 9:31pm by Hannah

Chemistry
Assume that a reaction occurs in which unknown substances R and S react to form unknown substances T and U. From the information below, determine the mass of substance T that will be formed if 45.0 grams of substance R reacts with 23.0 grams of substance S. (Assume that the ...
Tuesday, May 20, 2008 at 8:07pm by Daniel

Philosophy
The Continental Rationalists not only articulated elaborate views on substance but also utilized substance as the foundation of their metaphysics. Nevertheless, their views on substance, though similar in some respects, differ in important ways. How do their views on substance...
Monday, February 4, 2008 at 11:28pm by Joe

hernandez
find the molar enthalpy of vaporization for a substance, given that 3.21 mol of the substance absolve 28.4 kj of energy as heat when the substance changes from liquid to gas? show the work
Thursday, May 30, 2013 at 9:38pm by ady

Chemistry
An unknown substance has a mass of 16.3 g. The temperature of the substance increases by 20.1 degrees Celsius when 126 J of heat is added to the substance. What is the most likely identity of the substance? The table lists the specific heat capacities of select substances. ...
Tuesday, October 9, 2012 at 11:18pm by Anonymous

Science
Radioactive substance decays so that after t years, the amount remaining, expressed as a percent of the original amount, is A(t)=100(1.6)^(-t). a) Determine the function A, which represent the rate of decay of the substance. b) what is the half-life for this substance? c) ...
Tuesday, March 6, 2012 at 11:03pm by jessica

science HElp
Ph scale Which on is true A substance with ph is twice as acidic as substance with ph of 4. A subtances with ph 3 is 10 as acidic as substance with ph of 4. A substance with ph 3 twice as alkies as substances with ph 4. a substancs with ph 3 10 time alkies as substance with ph...
Wednesday, November 23, 2011 at 7:14pm by shan

algebra
Julie has 250 grams of a radioactive substance. The substance decays every hour. How long will it take until she has 20 grams of the substance left?
Monday, September 9, 2013 at 4:15pm by Sozy

chemistry
given 10.8 grams of substance y,if the substance absorbs 231 kilojoules of energy and the specfic heat of substance is 6.55 J/g*0C what is the heat change
Thursday, November 7, 2013 at 5:29pm by Heather

Pam
A 56.59 g sample of a substance is initially at 20.5 C. After absorbing 1267 J of heat, the temperature of the substance is 116.5 C. What is the specific heat (c) of the substance?
Thursday, December 5, 2013 at 3:24pm by Chemistry

Chemistry
Which of the following is correct? A)A substance with pH of 3 is 10 times as Acidic as a substance with a pH of 4. B)A substance with a pH 3 is twice as acidic as a substance with a pH of 4.
Thursday, April 12, 2012 at 11:21am by Lee

Math
A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...
Saturday, April 5, 2014 at 10:05pm by Vanessa

Math
A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...
Sunday, April 6, 2014 at 8:54pm by Vanessa

Chemistry help
A substance with pH of 3 is 10 times as Acidic as a substance with a pH of 4. *****or******* A substance with a pH 3 is twice as acidic as a substance with a pH of 4.
Saturday, April 14, 2012 at 4:42pm by Lee

psychology
1 which statement most accurately differentiates substance dependence from substance abuse? A substance dependence involves ongoing use of a drug despite the problems it causes in the person's functioning. B With substance dependence, the individual uses the drug daily C ...
Thursday, April 2, 2009 at 3:05pm by nia

Chemistry
Substance X (MW=356gm) is a weak acid. Its Ka is 1.7x10^-3. Calculate pH of725ml of the following solutions: a)Containing 0.187 mol of substance x b)containing 127gm of Substance x I have been trying to figure this problem out for hours now and do not get it. Please help me ...
Tuesday, April 16, 2013 at 11:54am by Grace

chemistry
Substance A has a specific heat of .650J/gK and substance B has a specific heat of .325J/gK. If 100 J of energy is applied to a 10 g sample of each substance, which will have a higher temperature?
Monday, September 19, 2011 at 8:51pm by Anonymous

chemistry
Substance A has a specific heat of .650J/gK and substance B has a specific heat of .325J/gK. If 100 J of energy is applied to a 10 g sample of each substance, which will have a higher temperature?
Monday, September 19, 2011 at 8:53pm by Anonymous

Chemistry
1. We identify substances from their physical and chemical properties. 2. If we know the density of a substance, we can calculate the mass of a sample from the volume or the volume from the mass. 3. The density of a substance is taken into account in determining how that ...
Wednesday, September 2, 2009 at 4:37pm by GK

Science
A polar substance is most soluble in ... ? A non-polar substance is most soluble in ... ? A generalized statement summarizing the effect of bond polarity on the solbility of a substance in a solvent is ... ?
Monday, January 5, 2009 at 6:07pm by Virginia

chemistry
Yes. 40.0g of a substance with molar mass of 100.09 = 0.4 mol of that substance. If the question on the quiz was as you quoted it (a "substance" and it was not identified as CaCO3) then M = 0.40 mols/0.50 L and if you worked it that way you worked it correctly. When a problem ...
Thursday, March 10, 2011 at 10:36am by DrBob222

chemistry
22. Choose the best description for a solid held together by London forces. A. This substance melts at -30 C to give a liquid that does not conduct electricity. B. This substance melts at 650 C and both the solid and liquid phases conduct electricity. C. This substance melts...
Sunday, February 13, 2011 at 3:32pm by Kathy R

Pre Cal
a radio actice substance decays so that half of the substance decays every 2 minutes. if 100 g of the substance are present initially, how many grams will be present after 4 minutes and 8 minutes respectively?
Sunday, July 24, 2011 at 7:48pm by Angela

Philosophy
Benedict Spinoza argues that substance is infinite and that God or Nature is the one substance. As a monist, Spinoza rejects ontological dualism. From this perspective, how does Spinoza understand thought and extension monistically, and what does he mean by characterizing the ...
Monday, February 4, 2008 at 11:26pm by Joe

Chemistry
46.9 g of a substance at 90.8C is added to 51.8 g of water at 24.8C. The final temperature of the water and substance is 40.5C. The specific heat of water is 4.184 J/gC. What is the specific heat of the substance? I think the equation that I need to use for this is C=Q/m...
Monday, March 8, 2010 at 4:25pm by Tiffany

Alegbra
Andrew measures the amount of a very unstable substance to be 100 moles. The half-life of this substance is 3 days (after 3 days, half is gone). Write an exponential function that models this situation where y is the amount of substance and x is time in days. Thank you for ...
Tuesday, May 1, 2012 at 6:58pm by Jessica

chemistry
In a chemical reaction, exactly 2 mol of substance A react to produce exactly 3 mol of substance B. How many molecules of substance B are produced when 26.5 g of substance A reacts? The molar mass of substance A is 21.9 g/mol. Step 1: Convert the mass of A to moles. Step 2: ...
Tuesday, September 24, 2013 at 10:07pm by bb

science
A substance that has a mass of 20g and volume of 10cm3. How much mass does one cm3 of this substance have? A substance with a mass of 125g and a volume of 25cm3. How much mass does one cm3 of this substance have? Please tell me how to do this.
Tuesday, October 22, 2013 at 5:05pm by Mi

Math
the concentration of a certain substance in our organism is given by the model Q9t) = Q(subscript 0) e^-0.1960t a) what quantity of substance is present in the organism of this individual 3 hours after ingestion? b) after how many hours will there only be 10% of this substance...
Thursday, April 7, 2011 at 12:51am by Ralph

Science
What is a mixture in which one substance spreads evenly throughout another substance
Monday, August 18, 2008 at 9:41pm by Jessica

Pyshical Science
50g of a substance has a volume if 100cm3. What is the density of the substance?
Thursday, February 4, 2010 at 10:10pm by Dixie

science
How is the temperature of a substance related to the energy of movement of the particles in the substance?
Wednesday, October 12, 2011 at 7:21pm by cassandra

Science
If the melting point of a substance is -39C, has the substance melted at 20C?
Wednesday, March 5, 2014 at 4:12pm by Miaya

calculus
assume the half-life of the substance is 31 days and the initial amount is 183.9 grams. (a) Fill in the right hand side of the following equation which expresses the amount A of the substance as a function of time t (the coefficient of t in the exponent should have at least ...
Thursday, September 16, 2010 at 4:40pm by trace

chemistry
a solid substance has a density of 4.36 g/ml. what is the volume of 30 g of this substance?
Monday, December 12, 2011 at 8:51pm by jessica lou

Chemistry
Are the following parameters stability indicating? 1) Viscosity of a substance 2) Optical rotation of a substance
Friday, April 13, 2012 at 9:07pm by jean

Chemistry
What property must a substance have if u want to use the substance to make an aqueous solution? Thank you
Sunday, October 21, 2012 at 1:35am by Seastone

science
what property must a substance have if you want to use the substance to make an aqueous solution
Tuesday, November 6, 2012 at 5:41pm by Anonymous

science
A substance is added to the solution of Barium sulphate,yellow precipitate is formed.What is that substance?
Wednesday, March 13, 2013 at 4:57am by prabodh

AP Physics
A student found an unknown substance. In an effort to identify the thermal properties of the substance, she isolated a specimen of 47 gram, and applied 290 J of heat energy to the specimen. If she measured the temperature of the specimen changed from 20 C to 25.7 C, what ...
Wednesday, December 2, 2009 at 11:59pm by Sasami

Science
A SUBSTANCE HAS A PH OF 3. IS THIS SUBSTANCE AN ACID OR A BASE ?
Wednesday, November 10, 2010 at 8:04pm by Anonymous

Physical Science
Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the substance have very different melting temperatures and densities. The unknown substance is most likely a ...
Sunday, September 25, 2011 at 4:12pm by Ryan

gorge
suppose you a piece of an unknown substance. describe how you would determine wether or not the substance was metal
Thursday, March 24, 2011 at 1:28pm by luis

chemistry
2. Keq = (products)/(reactants) and raise each substance to the exponent that the substance has as a coefficient in the balanced equation.
Wednesday, August 3, 2011 at 5:45pm by DrBob222

5th grade science
A substance seems to completely fill a container, but more can be forced in. The substance is a
Tuesday, February 14, 2012 at 8:01pm by Yamani

Chemistry
What property must a substance have if u want to use the substance to make an aqueous solution? Grade- 9
Sunday, October 21, 2012 at 1:49am by Seastone

algebra
Andrew measures they amount of a very unstable substance to be 100 moles. the half life of this substance is 3 days(after 3 days, half is gone). write an exponential function that models this situation where Y is the amount of substance and X is time in days. use your equation...
Friday, April 26, 2013 at 11:11pm by Anonymous

Chemistry
In a chemical reaction, exactly 2 mol of substance A react to produce exactly 3 mol of substance B 2A ---> 3B How many molecules of substance B are produced when 27.9 g of substance A reacts? the molar mass of substance A is 24.7 g/mol STEP 1: convert the mass of A to moles...
Saturday, January 22, 2011 at 5:10pm by Mark

scientist
Pretend you are a scientist and you just found a solid substance in the ground where you were digging. What types of tests would you do on this substance? How would you determine if it is a rock or a mineral? Describe your substance (yes you can make something up here that ...
Monday, April 9, 2012 at 9:46pm by Bell

Science
My mistake. We oftenly describe density as the "heaviness" of a substance. It is th mass per unit volume of a substance.
Tuesday, April 6, 2010 at 7:42pm by Anonymous

Chemistry
Convert 6.42x10^23 atoms a pure substance to moles of that substance. That is all it says. Please help. Thank you.
Thursday, September 12, 2013 at 3:26pm by Miley

Thermodynamic
N2 is described by its state properties of temperature @ - 100 Degree C, and pressure @10.0 MPa. Determine if it is reasonable to assume that the given substance behaves as an ideal gas at the specified state. If the substance is determined as a real gas or non-ideal substance...
Monday, January 10, 2011 at 1:19pm by chris

Chemistry
What is the specific heat of a substance if 26.0 kJ are required to raise the temperature of 250. g of the substance from 34.0C to 201.0C?
Sunday, March 7, 2010 at 10:17pm by Tiffany

Chemistry
What is the specific heat of a substance if 35.5 kJ are required to raise the temperature of 345 g of the substance from 69.0C to 150.0C?
Monday, March 8, 2010 at 4:28pm by Megan

science
A substance seems to completely fill a container, but more can be forced in. Is the substance a solid, liguid, gas or none of these????
Wednesday, May 12, 2010 at 12:49pm by sue

physics
90 g of water at 25C mixed with 50g of another substance at 100C result in 45C what is specific heat of that substance
Tuesday, January 29, 2013 at 9:57pm by sam

Physics
A radioactive substance decays from 2.0kg to 1.6kg in 156 days. What is the decay constant and the half life of the substance?
Tuesday, August 6, 2013 at 11:28pm by Alice

Chemistry
I think you are right but I like this way of doing it better. loss of heat from substance + heat gained by water = 0 [mass substance x specific heat substance x (Tfinal-Tinitial)] + [mass water x specific heat water x (Tfinal-Tinitial) = 0 Solve for specific heat substance.
Monday, March 8, 2010 at 4:25pm by DrBob222

Chemistry
Which substance ( HI or Xe ) has the higher boiling point? Its HI but chose one of the most appropriate reason. 1. Both substances are nonpolar but the higher boiling includes hydrogen bonding 2. Both substances are nonpolar but the higher boiling is more polarizable 3. The ...
Saturday, October 12, 2013 at 11:11pm by ss01

Chem
Substance X raises the boiling point of 150g of water to 101.3 C. What is the molecular mass of substance X? (assume x does not ionize/ is not volatile)
Tuesday, January 15, 2008 at 10:14pm by Anonymous

Science
What is the specific heat of an unknown substance if 2000 J of energy are required to raise the temperature of 4 grams of the substance 5 degrees Celsius?
Friday, September 10, 2010 at 11:21am by jason

9th grade
An uknown substance from planet x has a density of 10g/ml.it occupies a volume of 80ml. what is the mass of this unknown substance
Monday, September 27, 2010 at 4:45pm by gasharee

9th grade
An uknown substance from planet x has a density of 10g/ml.it occupies a volume of 80ml. what is the mass of this unknown substance
Monday, September 27, 2010 at 5:00pm by gasharee

chemistry
The heat of vaporization of a substance is 2900 J/g at its boiling point of 313C. How much of this substance can be vaporized if 58700 J of energy are available?
Monday, January 17, 2011 at 5:36pm by dave

Chemistry Help!!
What is the specific heat of an unknown substance if 2000 J of energy are required to raise the temperature of 4 grams of the substance 5 degrees Celsius
Wednesday, January 19, 2011 at 11:32am by Anonymous

chemistry
What is the specific heat of an unknown substance if 2000 J of energy are required to raise the temperature of 4 grams of the substance 5 degrees Celsius?
Wednesday, May 30, 2012 at 9:22am by amber

chemistry
what is the density of a substance if a 2.50 ml sample has a mass of 0.880g at room temperature? what is the specific gravity of the substance?
Sunday, September 9, 2012 at 11:25pm by Sasha nelson

Calculus-derivatives
Verify if these are correct answers. 1. The derivative of f(x)=e^2x -e^-2x is f'(x)=2e^2x - 2e^-2x? 2.A certain radioactive substance is decaying so that at time t, measured in years, the amount of the substance, in grams, given by the function f(x)=3e^-3t. What is the rate of...
Tuesday, March 6, 2012 at 7:09pm by Matthew

Chemistry
Which substance ( HBr or HF ) has the higher boiling point? Its HF but chose one of the most appropriate reason. 1. Both substances are nonpolar but the higher boiling includes hydrogen bonding 2. Both substances are nonpolar but the higher boiling is more polarizable 3. The ...
Saturday, October 12, 2013 at 11:11pm by ss01

Physics
A portion of an electric circuit connected to a 7 ohm resistor is embedded in 1.20 kg of a solid substance in a calorimeter. The external portion of the circuit is connected to a 100 volt power supply. (a) Assuming that all the heat generated by the resistor is absorbed by the...
Sunday, May 10, 2009 at 5:46pm by Fred

science
chemical: burn, puts off an odor, forms precipitate, new substance physical: changes state, same substance
Tuesday, March 4, 2008 at 10:07pm by emily

Identify the substance
There was a substance I used in a lab for chem class and I`m not too sure what it was. They were tiny white balls about a millimeter in diameter. What would they be?
Monday, March 2, 2009 at 1:29am by Lena

chemistry
The primary substance from which all other chemical compounds and substances are made is a____________. A) element B) compound C) mixture D) pure substance
Thursday, September 15, 2011 at 7:25pm by kiara

science
The primary substance from which all other chemical compounds and substances are made is a____________. A) element B) compound C) mixture D) pure substance
Thursday, September 15, 2011 at 7:49pm by kiara

chem
The primary substance from which all other chemical compounds and substances are made is a____________. A) element B) compound C) mixture D) pure substance
Thursday, September 15, 2011 at 8:10pm by nick

science
A substance seems to completely fill a container, but more can best forced in. The substance is a__________. A. solid B. gas C. liquid D. none of these
Tuesday, October 18, 2011 at 10:00pm by stephanie

chem
How do I calculate the rate of a reaction of a substance using the slope of the lines and stoichiometry of the reactions in moles/sec. I also know that the molarity of that substance.
Thursday, February 13, 2014 at 6:27pm by rachel

science
Technician A and Technician B are examining the same substance. Technician A records the mass, volume, and weight of the substance and decides that it is sugar. Technician B records the melting point, density, and boiling point of the substance and decides that it is salt. ...
Sunday, September 27, 2009 at 4:32pm by jane

math
if the rate for radioactive decay for a substance is r=-.0063 and time is being measured in days how do you find the half-life of the substance to the nearest hour?
Monday, March 30, 2009 at 1:16am by mike

math
an extremely volatile substance, Ofnetite, has a half-life of 25 minutes. Find the percentage decrease of this substance in the first two hours.
Sunday, November 8, 2009 at 9:57pm by katy

biology
Substance X is converted to substance Y in a chemical reaction. What role would a catalyst play in this scenario? A. It would increase the solubility of substance X into the solvent needed to speed up the reaction. B. It would speed up the reaction by becoming part of the ...
Wednesday, November 6, 2013 at 8:09pm by hannah

SCIENCE
The size, mass, and arrangement of atoms affect the density of a substance. If a substance has a low density, what can you guess about the size, mass and arrangement of the atoms that make up that substance?
Tuesday, July 16, 2013 at 8:46pm by Amy

science
g) Use the substances given in table 1 to calculate the volume of 270 g of aluminum. The densities of substances given: glycerol (substance a) = 0.97 g/mL isoprop (substance b) = 1.20 g/mL water (substance c) = 0.85 g/mL How would i know what the mass is? Would i use the G.R.A...
Tuesday, September 29, 2009 at 4:36pm by becca

chemistry
According to reference table G,which substance forms an unsaturated solution when 80 grams of the substance is dissolved in 100grams of hydrogen 2 oxygen at 10 degrees celsius?
Monday, April 19, 2010 at 10:09pm by felisha

Algebra
I need help, I don't understand this at all! I want to use Orange Juice. So what do I do? Find the hydrogen ion content of a substance of your choice. Using this hydrogen ion content, show how to find the pH of the substance using the formula. Is this substance acidic or basic...
Friday, December 14, 2007 at 10:20am by Cupcake

Science (Asap)
Compare and contrast: When you combine two or more different substances,you get a mixture.The substance aren't mixed evenly.Their properties don't change.The substance can be separated from the mixture.For example,sand is a mixture that can be separated into rocks and broken ...
Monday, May 2, 2011 at 7:43pm by Frances

chemistry
i had 2 question left to finish but i cant really undersdand how to do it 9)design an elextrochemical cell using Pb(s) and Mn(s) and theire solutions and answer the following questions: i answerd a-i all that is left is j which is: indicate the substance oxidise,substance ...
Tuesday, July 24, 2012 at 6:09pm by sam

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