Chemistry Math Review

What is the empirical formula if you have 88.80% copper and 11.20% oxygen?

• Cu₃O₈
• CuO₄
• Cu₂O
• Cu₄O₁₀

What is the molecular formula for a compound with the empirical formula: K₂SO₄ and a molecular mass of 696g.

• K₂SO₄ 
• K₈SO₁₆
• K₈S₄O₈ 
• K₈S₄O₁₆ 

Which of the following represents an empirical formula?

• H₂O₂
• HC₂O₄
• H₂O₆
• H₁₂O₄₈

Calculate the density of the cube. (Hint: calculate the volume of the cube using V= Bh)

• 0.33 g/cm³
• 0.4 g/cm³
• 0.6 g/cm³
• 0.5 g/cm³

How close a measurement is to the true value is called..

• Accuracy

• Precision

• Significant

• Estimate

When a measurement is repeatable and consistent it is said to have...

• High precision
• Low precision
• High accuracy
• Low accuracy

The students measured length during a science experiment, they got 12 cm. But the actual measurement was 14.25 cm. What was the percent error?

• 15.79%

• 18.75%

• 2.25%

• 18%

There are __?__ significant digits in the number 0.00076

• 2
• 4
• 5
• 6

How many significant figures does the following number have: 0.002040

• 6
• 4
• 3
• 2

What is the wavelength for a quantum of light with energy of 7.56x10^-19J? (λ=hc/E) 

• 2.62x10^-7m
• 2.62x10⁷m
• 2.64x10^-45m
• 2.64x10⁴⁵m