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100
Avagadro's number is...
What is 6.02x10^23
100

The empirical formula for C6H8

What is C3H4

100

Which is the mass of 8 moles of NaCl?

What is 468 Grams

100

The percent of hydrogen in water.

What is 11.2 %

100
This is the correct when the following are put in increasing order by unit size. 


mole                molecule    atom

 What is atom, molecule, mole

200
What would be the ratio needed to change 5.1 moles of Al to atoms of Al?

What is 6.02x10^23 atoms Al/ 1 mole Al

200

An unknown compound was found to have a percent composition as follows: 47.0 % potassium, 14.5 % carbon, and 38.5 % oxygen. What is the empirical formula?

What is KCO2

200

Calculate the number of molecules in 4.0 mol H2O.

What is 2.4 x 10^24

200

The percent of potassium in KBr

What is 32.9 %

200

What needs to be done to the balance before weighing anything.

What is taring or (zeroing) the balance

300

How many moles of atoms are in one mole of AlPO4?

What is 6 moles

300

The substances that have the same empirical formula are: A) CH2O  B) C6H12O6   C) C2H4O2

D)C7H5O2

What are A and B and C

300
Copper (Cu) is a transition element used in the making of coins. Calculate the mass in grams of 0.0420 moles of copper.
What is 2.67 g
300

The molar mass of MgS*2H2O

What is 92.42 g/mol

300

Which of the following sets of data  all represent the same amount with the correct units?

a)  1 mole  Ca ,    20 g Ca,    6.02x1023 atoms of Ca

b)  0.5 mole H2O,   3.01x1023 formula units H2O, 

9 g H2O

c)  1 mole NaCl,  58.5 g NaCl, 6.02x1023 formula units

What is (c)?

400
What is the molar mass of Ca(OH)2?
What is About 74 g/mol
400

A compound is made of 40.68% Carbon, 5.12% hydrogen and 54.20% oxygen. What is the empirical formula?

What is CH6O ?

400
How many molecules are in 3.6 grams of NaCl?
What is 3.7 x 10^22 molecules
400

Which is the percent composition of oxygen in the compound Mg2(PO4)3?

What is 57.6 %?

400

The formula for Ammonium nitrate.

What is (NH4)NO3

500
What would be the mass of 4.5 x 1025 molecules of CO2?

What is 3289 g?

500

The empirical formula of a compound is NO2. Its molecular mass is 92 g/mol. What is its molecular formula?

What is N2O4

500

Two balloons are blown up, each with a different gas. The first balloon has 1.2 x 1024 atoms of Helium. The second ballon has 16 grams of oxygen. Which balloon has a larger quantity of gas?

What is oxygen (0.5 mol vs. He = 2 moles)

500

Which is the formula for a compound that contains 64.75 g nitrogen and 185.25 g oxygen?


What is N2O5

500

This is what causes a bond to be polar. 

What is an electronegativity difference between 0 and 1.7?