chem test
Which of the following best describes one mole of potassium sulfate, K2SO4?
C.
It has a mass of 174.3 g.
The molar mass of copper(II) sulfate pentahydrate, CuSO4.5H2O, is
e.
249.6 g/mol
The number of moles of H in three moles of copper(II) sulfate pentahydrate, CuSO4.5H2O, is
D.
30
The number of carbon atoms present in 0.062 mol of acetic acid, CH3COOH, is
A.
7.5 x 10^22 atoms
The molar mass of a sample of atoms of an element was found to be 107.9 g/mol. This element is likely
A.
Silver
The number of atoms represented by the formula Ca(NO3)2
C.
9
The volume of a mole of any ideal gas at STP is equal to
a. 22.4 L
Standard temperature and pressure are equal to
c.
O C and 101.3kpa
How is 0.00025 written in scientific notation?
d.
2.5 x 10^4
How would you express 87.6 g of aluminum sulfate, Al2(SO4)3(s), as an amount?
a.
0.256 mol
What amount of chlorine makes up 102.5 g of chlorine gas?
b.
1.44 mol
What is the average atomic mass of neon?
c.
20.179 u
How many oxygen atoms are in a 1.05 mol sample of CO2(g)?
c. 6.02 x 10^23 atoms
Ascorbic acid (vitamin C) has the formula C6H8O6(s). How many hydrogen atoms are in one molecule of
ascorbic acid?
d.
8
How many formula units are in 1.56 mol of potassium permanganate, KMnO4(s)?
b. 9.39 x 10^23 formula units
Oxalic acid, H2C2O4(s), is isolated from clover leaves and is used in the manufacture of paints and textiles.
How many oxygen atoms are in a 2.25 mol sample of oxalic acid?
e. 5.42 x 10^24 atoms
How many moles are in a sample of magnesium chloride, MgCl2(s), that is made up of 3.97 x 10^25 formula units?
b.
65.9 mol
Sulfur trioxide, SO3(g), is a known contributor to the problem of acid precipitation, because it reacts with water to form sulfuric acid. What amount of sulfur trioxide is in a sample that contains 6.54 x 10^21
molecules?
a.
0.0109 mol
Propane, C3H8(g), is a common barbecue fuel. What amount of propane is in a sample that contains 2.31 x 10^26 carbon atoms?
b.
127 mol
A pure sample of butane, C4H8(l), contains 3.97 1022 hydrogen atoms. How many moles of butane are there in this sample?
a.
0.00824 mol
What is the molar mass of CaCl2(s)?
d.
110.98 g/mol
For which compound does a 0.121 mol sample have a mass of 22.9 g/mol?
d.
SnCl2(s)
What is the mass of 6.02 x 10^24 formula units of NaCl?
c.
584g
What is the mass of 6.02 x 10^24 formula units of NaCl?
c.
584g
How many grams are in 2.97 moles of Ca3(PO4)2?
e.
921g
Perfluorooctanoic acid, C7F15COOH, is used to coat cookware. It is commonly known as TeflonTM. What is the molar mass of TeflonTM?
c. 414 g/mol
What amount of Ba(NO3)2 has a mass of 2.56 g?
a. 0.00980 mol
Swiss cheese gets its characteristic smell in part from propanoic acid, C2H5COOH(l). What amount of propanoic acid has a mass of 425 g?
b.
5.74 mol
If a sample of ZnCl2(s) contains 2.56 1024 Zn2+ ions, what is the mass of the sample?
d.
579g
If a sample of ZnCl2 contains 2.56 1024 chloride ions, what is the mass of the sample?
A.
289g
Which compound has the greatest molar mass?
B.
AlCl3(s)