4:pre/post questions

what is the atomic mass of helium 1 amu 3 amu 4 amu 8 amu

4 amu

The second step in converting between the mass of a compound and moles of a compound is to use the molar mass to convert grams to moles. true or false

true

Calculate the moles of anhydrous CuSO4 present in a sample with 0.5 g CuSO4 at a molar mass of 159.61 g/mol. 0.00313 0.00853 0.00710 0.00626

0.00313

After heating a sample of hydrated CuSO4, the mass of released H2O was found to be 2.0 g. How many moles of H2O were released if the molar mass of H2O is 18.016 g/mol? 0.004 0.111 9.031 0.222

0.111

The element oxygen has a molar mass of 15.999 grams, thus one mole of oxygen is equal to _____ g/mol. 31.998 15.999 x 1023 15.999 31.998 x 1023

15.999

Based on the correct answer to question 7, calculate the ratio of moles of H2O to moles of anhydrous CuSO4 if there were 0.085 mols of released H2O. 12 10 27 5

27

The molar mass of carbon dioxide (CO2) is _____. 44.0 g/mol 47.0 g/mol 43.0 g/mol 42.5 g/mol

44.0 g/mol

Arrange each chemical in order of mass from smallest to largest 3.0 moles ch3ch2oh 2.0 moles n2 5.0 moles h2 1.5 moles na 1.0 moles pbcl2

5.0 moles h2 1.5 moles na 2.0 moles n2 3.0 moles ch3ch2oh 1.0 moles pbcl2

There are _____ atoms in 12 grams of pure carbon (12C). 12.022 x 1023 6.022 x 1023 4.023 x 1023 1.00 x 1023

6.022 x 1023

When copper sulfate heptahydrate is heated, how many moles of water are available to be released? 1 4 7 9

7

Based on the correct answer to question 8, what is the empirical formula for hydrated CuSO4? CuSO4●27H2O CuSO4●12H2O CuSO4●10H2O CuSO4●H2O

CuSO4●27H2O

A mole is a unit of measure, describing the amount of a chemical substance that contains as many atoms, molecules, or formula units as there are in exactly 12 grams of pure oxygen. true or false

false ; pure carbon

Water is released from a hydrate by _____. heating the hydrate cooling the hydrate adding water to the hydrate none of the above

heating the hydrate

A hydrate is a compound in which water molecules are a part of the crystalline structure. true or false

true

One mole of a compound has the mass that is equal to the molecular mass. true or false

true

The first step when converting between mass of a compound and moles of a compound is to determine the molar mass of the compound.

true; first determind the molar mass of the compound