chemistry 11.1-4 quiz
c
For which of the following conversions does the value of the conversion factor depend upon the formula of the substance? a. volume of gas (STP) to moles b. density of gas (STP) to molar mass c. mass of any substance to moles d. moles of any substance to number of particles
b
How many moles of tungsten atoms are in 4.8x10^25 atoms of tungsten? a. 8.0x10^2 moles b. 8.0x10^1 moles c. 1.3x10^-1 moles d. 1.3x10^-2 moles
b
To determine the formula of a new substance, one of the first steps is to find the a. molar mass b. percent composition c. volume at STP cd. number of particles per mole
b
What is the percent by mass of carbon in acetone, C^3H^6O? a. 20.7% b. 62.1% c. 1.61% d. 30.0%
a
all of the following are equal to Avogadro's number except a. the number of atoms of bromine in 1 mol Br^2 b. the number of atoms of gold in i mol Au c. the number of molecules of nitrogen in 1 mol N^2 d. the number of molecules of carbon monoxide in 1 mol CO
c
how many atoms are in 3.5 moles of arsenic atoms? a. 5.8x10^-24 atoms b. 7.5x10^1 atoms c. 2.1x10^24 atoms d.1.7x10^23 atoms
d
if 20.0 grams of Ca combines completely with 16.0 grams of S to form a compound, what is the percent composition of Ca in the compound? a. 1.25% b. 20.0% c. 44.4% d. 55.6%
c
if 60.2 grams of Hg combines completely with 24.0 grams of Br to form a compound, what is the percent composition of Hg in the compound? a. 28.5% b. 39.9% c. 71.5% d. 60.1%
a
the mass of a mole of NaCl is the a. molar mass b. atomic mass c. molecular mass d. gram atomic mass
d
what SI base unit is used to measure the number of representative particles in a substance? a. kilogram b. ampere c. kelvin d. mole
c
what information is needed to calculate the percent composition of a compound? a. the weight of the sample to be analyzed and its density b. the weight of the sample to be analyzed and its molar volume c. the formula of the compound and the atomic mass of its elements d. the formula of the compound and its density
d
what is the mass in grams of 5.90 mol C^8H^18? a. 0.0512g b. 19.4g c. 389g d. 673g
d
what is the mass of oxygen in 250 g of sulfuric acid, H^2SO^4? A. 0.65 G B. 3.9 G C. 16 G D. 160 G
c
what is the molar mass of (NH^4)^2CO^3? a. 144g B. 138g c. 96g d.78g
c
what is the number of moles in 432g Ba(NO^3)^2? a. 0.237 mol b. 0.605 mol c. 1.65 mol d. 3.66 mol
b
what is the number of moles of beryllium atoms in 396 g of Be? a. 0.25 mol b. 4.0 mol c. 45.0 mol d. 320 mol
d
what is the percent composition of carbon, in heptane, C^7H^16 a. 12% b. 19% c. 68% d. 84%
c
what is the percent composition of chromium in BaCrO^4? a. 4.87% b. 9.47% c. 20.5% d. 25.2%
b
what is true about the molar mass of chlorine gas? a. the molar mass is 35.5g b. the molar mass is 71.0g c.the molar mass is equal to the mass of one mole of chlorine atoms d. none of the above
b
which expression represents the percent by mass of nitrogen in NH^4NO^3? a. 14 g N/80 g NH^4NO^3 X 100% b. 28 g N/80 g NH^4NO^3 X 100% c. 80 g NH^4NO^3/14 g N X 100% d. 80 g NH^4NO^3/28 g N X 100%
d
which of the following compounds has the highest oxygen content by weight? a. Na^2O b. CO^2 c. BaO D. H^2O
d
which of the following compounds has the lowest percent gold content by weight? a. AuOH b. Au(OH)^3 c. AuCl^3 d. AuI^3
c
which of the following elements exists as a diatomic molecule? a. neon b. lithium c. nitrogen d. sulfur
d
which of the following is NOT a representative particle? a. atom b.cation c. anion d. all of the above
a
which of the following is not true about atomic mass? a. the atomic mass is 12g for magnesium b. the atomic mass is the mass of 1 mole of atoms c. the atomic mass is found by checking the periodic table d. the atomic mass is the number of grams of an element that is numerically equal to the mass in amu
