Chemistry Quiz

What is the empirical formula of a compound that is 40% sulfur and 60% oxygen by weight?

• SO

• S6O4

• SO2

• SO3

What is the number of moles of beryllium in 36 g of Be?

• 4.0 mol

• 320 mol

• 45.0 mol

• 0.25 mol

What is the percent composition of chromium in BaCrO4?

• 4.87%

• 20.5%

• 25.2%

• 9.47%

What is the number of moles in 432 g Ba(NO3)2?

• 3.66 mol

• 0.605 mol

• 1.65 mol

• 0.237 mol

How many atoms are in 3.5 moles of arsenic atoms?

• 2.1 x 10^24 atoms

• 1.7 x 10^23 atoms

• 5.8 x 10^40 atoms

• 7.5 x 10^4 atoms

How many hydrogen atoms are in 5 molecules of isopropyl alcohol, C3H7O?

• 5 x (6.02 x 10^23)

• 5

• 35 x (6.02 x 10^23)

• 35

What is the molar mass of AuCl3?

• 96 g

• 130 g

• 232.5 g

• 303.6 g

What information is needed to calculate the percent composition of a compound?

• the weight of the sample to be analyzed and its molar volume

• the weight of the sample to be analyzed and its density

• the formula of the compound and its density

• the formula of the compound and the atomic mass of its elements

What is the mass in grams of 5.90 mol C8H18?

• 19.4 g

• 389 g

• 0.0512 g

• 673 g

How many moles of tungsten atoms are in 4.8 x 10^25 atoms of tungsten?

• 1.3 x 10^-1 moles

• 1.3 x 10^2 moles

• 8.0 x 10^2 moles

• 8.0 x 10^1 moles