Mole Conversions & Chemical Formula Math

What is the empirical formula for this compound?

• C₆H₂N₆O₃
• C₄HN₅O₁₀
• CH₃NO₂
• CH₅NO₃

Tags

NGSS.HS-PS1-7

If the empirical formula for a sugar is CH₂O, what is a possible molecular formula for that sugar?

• C₆H₁₂O₆
• C₂H₂O₂
• CH₄O
• none of the above

Find the percentage composition of  Mg in Mg₃(PO₄)₂.
   

• 27.75% Mg
• 23.57% Mg
• 48.68% Mg
• 13.45% Mg

Which is the correct molar mass for the compound CaBr₂?

• 120 g/mol
• 200 moles
• 240 grams
• 200 g/mole

Which term is used to describe the percent by mass of any element in a compound?

• hydrate
• molecular formula
• percent composition
• empirical formula

Which term is used to describe the lowest whole-number ratio of elements in a compound?

• hydrate
• molecular formula
• percent composition
• empirical formula

What is the percent composition of phosphorous in Zn₃(PO₄)₂?

• 16.1%
• 9.66%
• 50.1%
• 24.01%

A 60.00g sample of tetraethyl lead, a gasoline additive, is found to contain 38.43g lead, 17.83g carbon, and 3.74g hydrogen.  Find its empirical formula.

• PbCH
• Pb₂C₈H₁₀
• PbC₈H₂₀
• PbC₄H₁₀

Tags

NGSS.HS-PS1-1

The molar mass of an element is the mass of one

• atom of the elemt
• crystal of the element
• gram of the element
• mole of the element

The empirical formula is always the accepted formula (molecular formula) for a(n)

• atom
• molecule 
• covalent compound
• ionic compound