1 STEP CONVERSIONS
What is Avogadro's Number?
6.02 x 1023
1. How do you go from grams to moles and moles to grams?
2. How do you go from number of particles to moles and number of particles to moles?
1. molar mass
2. Avogadro's number
What's the FIRST thing you need to find out to do these problems?
you need the formula!!!!!!!
T/F: Empirical formulas are the simplest whole number ratio.
True
T/F: Molecular formulas show exactly what's in the formula.
True
Formula Units are for ______ compounds. Molecules are for ________ compounds. Atoms are for __________.
Ionic
Covalent
Elements
How many grams are in 3.011×1023 molecules of CO2 ?
22.0 g
In H₂O, what percent of the mass is oxygen?
88.90% O
A compound contains 40% C, 6.7% H, 53.3% O. Find the empirical formula.
CH₂O
The empirical formula of a compound is CH₂O. Its molar mass is 180 g/mol. What is the molecular formula
C₆H₁₂O₆
How many atoms are in 1 mole of carbon?
6.02 X 1023 ATOMS
How many molecules are in 36 g of H₂O?
1.2 × 1024 molecules
Calculate the percent by mass of C in C₆H₁₂O₆
40%
A compound contains 70% Fe and 30% O. What is the empirical formula?
Fe₂O₃
Empirical formula: NH₂. Molar mass: 32 g/mol. Find the molecular formula.
N₂H₄
What is the mass of 1 mole of H₂O?
18.02 g
How many grams are in 1.204×1024 molecules of Carbon Tetrahydride?
32 g
What is the percent by mass of Na in NaCl
39.3%
A compound has 52.1% C, 34.7% O, 13.2% H. Determine the empirical formula.
C₂H₅O
A compound contains 54.5% carbon, 9.1% hydrogen, and 36.4% oxygen. The molar mass of the compound is 88 g/mol. What is the molecular formula?
C₄H₈O₂
How many atoms are in 3.01 × 10²³ atoms of sodium (Na)?
0.500 mol
A sample contains 44 g of CO₂. How many molecules of CO₂ are in the sample?
6.02 x 1023 molecules
A sample has 5 g of C, 10 g of H, and 85 g of O. What is the percent by mass of hydrogen?
10%
A compound contains 5.84% H, 58.64% C, 35.52% O. Determine the empirical formula.
C₃H₆O
A compound contains 48.6% carbon, 8.1% hydrogen, and 43.3% oxygen. The molar mass of the compound is 148 g/mol. What is the molecular formula?
C₆H₁₂O₄