Oxygen and Empirical Formula

What is the empirical formula of a compound that contains 75% Ag and 25% Cl by mass? AGCL

Calculate the approximate number of molecules in a drop of water with a mass of 0.10 g.
3 x 1021 molecules

What is the percentage composition of CaSO4?
29.44% Ca, 23.55% S, 47.01% O

What mass of calcium bromide is needed to prepare 150.0 mL of a 3.50 M solution? (Assume that the molecular weight of CaBr2 is 200.618 g/mol)
105 g

Nitrous oxide (N2O), or laughing gas, is commonly used as an anesthetic in dentistry and surgery. How many moles are present in 8.4 liters of nitrous oxide at STP?
0.375 moles

How many moles of gas molecules will be present in 5000 L of air at STP?
223.2 mol

How many molecules are in 1 mol of sucrose (C12H22O11)?
| |6.02 × 1023 molecules |

| |What is the empirical formula of a compound that contains 3.609 g calcium and 6.384 g chlorine by mass? |

CaCl2

During photosynthesis, plants take in carbon dioxide and water and convert it into glucose and oxygen. If a plant makes 30 grams of glucose (C6H12O6), how many moles of glucose has it produced?

0.17 moles
The health of bones depends upon a good supply of calcium. If a person consumes 0.06 g of calcium, how many moles of calcium did he consume?
1.5x10-3 mol

What is the empirical formula of a compound that contains 20% calcium and 80% bromine by mass?
CaBR2

Calculate the number of hydroxide ions present in 0.250 mol of Ca(OH)2.
3.01x1023

|What is the volume occupied by 0.25 moles of Nitrogen at STP? |
| |

5.60

What is the molecular formula for a compound with a molar mass of 26 g/mol and an empirical formula of CH?
C2H2

|The molar mass of a compound is 92.0 g/mol. It contains 14.7 g N and 33.6 g O. What is its molecular formula? |
| |

N204

14.7 grams of magnesium reacts completely with 9.7 grams of oxygen to form magnesium oxide (MgO). What is the percent composition of the magnesium oxide?
60.2% magnesium; 39.8% oxygen