Scientific Notation
Molar Mass
Conversions
100

Which of these numbers is the largest? 

2.5*104   or   4.7*103    or   9000

2.5*104

100

What is the molar mass of MgBr2?

Answer should be properly rounded to 2 decimal places. 

184.11 g

100

If you have 0.0052 moles of carbon, how many carbon atoms do you have?

Answer should have the right number of sig figs. 

3.1 * 1021 atoms

200

Which of these numbers is the largest? 

0.00030    or  5.2*10-5    or    1.9*10-3

 1.9*10-3

200

What is the molar mass of Al(NO2)3?

Answer should be properly rounded to 2 decimal places. 

165.01 g

200

How many moles of lithium are in a 30.0 g sample of it?

Answer should have the right number of sig figs. 

4.32 moles

300

Write this number in scientific notation. 

Your answer should have the same number of sig figs!

250,000,000,000

2.5 * 1011

300

What is the molar mass of calcium chloride?

Answer should be properly rounded to 2 decimal places. 

CaCl2

110.98 g

300

If you have 0.500 moles of MgI2, how many grams do you have?

139 g

400

Write this number in scientific notation. 

Your answer should have the same number of sig figs!

0.00070

7.0 * 10-4

400

What is the molar mass of ammonium oxide?

Answer should be properly rounded to 2 decimal places. 

(NH4)2O

52.10 g

400

How many atoms are in a 7.0 g sample of boron?

3.9 * 1023 atoms

500

Write this number in standard notation. 

Your answer should have the same number of sig figs!

9.8*1012

9,800,000,000,000

500

What is the molar mass of beryllium phosphate?

Answer should be properly rounded to 2 decimal places. 

Be3(PO4)2:

216.97 g

500

What is the mass of a sample that contains 2.000*1020 molecules of H2O?

Answer should have the right number of sig figs. 

0.005985 g

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