Mole Calculations Practice

How many moles of tungsten atoms are there in 4.8 x 10²⁵ atoms of tungsten?

• 1.3 x 10-1 moles

• 8.0 x 10-1 moles

• 1.3 x 10-2 moles

• 80 moles

Tags

NGSS.HS-PS1-7

How many atoms are there in 5.7 mol of hafnium?

• 3.43 x 10²⁴ atoms

• 1.06 x 10²² atoms

• 1.06 x 10²³ atoms

• 3.43 x 10²³ atoms

How many ammonium ions are there in 5.0 mol (NH4)2S?

• 3.4 x 10²

• 6.0 x 10²⁴

• 6.0 x 10²⁵

• 3.0 x 10²⁴

All of the following are equal to Avogadro's number EXCEPT _____.

• the number of atoms of gold in 1 mol Au

• the number of atoms of bromine in 1 mol Br2

• the number of molecules of carbon monoxide in 1 mol CO

• the number of molecules of nitrogen in 1 mol N2

Tags

NGSS.HS-PS1-7

What is the molar mass of chromium III sulfate ?

• 200.0 g

• 344.2 g

• 288.0 g

• 392.2 g

What is the mass in grams of 5.90 mol octane?

• 673 g

• 0.0512 g

• 389 g

• E) 3.55 x 10²⁴ g

How many moles of CaBr2 are there in 5.0 grams of CaBr2?

• 1.0 x 10³ mol

• 2.5 x 10^-2 mol

• 4.2 x 10^-2 mol

• 4.0 x 10¹ mol

Tags

NGSS.HS-PS1-7

What is the number of moles in 9.63 L of H2S gas at STP?

• 3.54 mol

• 0.104 mol

• 216 mol

• 0.430 mol

A 22.4-L sample of which of the following substances, at STP, would contain 6.02 x 10²³ molecules ?

• sulfur

• cesium iodide

• iodine

• oxygen

Which of the following gas samples would have the largest number of molecules at STP?

• 7.0 L O2

• 0.007 L SO3

• 0.10 L Xe

• 12.0 L He