Counting Atoms
What is the atomic number of hydrogen?
1
MgCl2 ---> Mg +Cl2
MgCl2 ---> Mg +Cl2
(Already balanced)
What is avogadro's number?
6.02x1023
How many moles are there in 6.02x1023 particles?
1 mole
What is chemistry the study of?
Matter
How many protons does oxygen have?
8
H2 + O2 --> H2O
2H2 + O2 --> 2H2O
Why do we have to include the same unit on the numerator and denominator for stoich problems?
To cancel out units
How many grams of H2O are there in 1 mole?
18 grams
What particles are in the nucleus of an atom?
Protons and Neutrons
How many neutrons does the average Argon have? (Molar mass of 39.948)
20
Mg(OH)2 + HCl ---> MgCl2 + H2O
Mg(OH)2 + 2 HCl ---> MgCl2 + 2 H2O
If I wanted to convert from moles to grams, what conversion factor would I use?
1 mole = 1 Molar Mass
How many liters are there in 50 grams of water vapor?
62 Liters
What does stoichiometry mean?
Measurement of elements
28
CH4 + O2 ---> CO2 + H2O
CH4 + 2 O2 ---> CO2 + 2 H2O
If I wanted to convert from particles to liters, what conversion factor would I use?
6.02x1023 particles = 22.4 liters
How many grams are there in 3.5 moles of oxygen gas?
112 grams
How does the atomic number and mass number change in alpha decay?
Mass number goes down by 4, atomic number goes down by 2
Rank the following from lowest valence electrons, to highest number of valence electrons
Bromine, Nitrogen, Carbon, Lithium, Neon
Lithium, Carbon, Nitrogen, Bromine, Neon
NH3 + O2 ---> NO + H2O
4 NH3 + 5 O2 ---> 4 NO + 6 H2O
Set up the boxes to calculate how many particles there are in 15 grams of sodium
15 grams sodium x (6.02x1023 particles / 22.9 grams)
How many particles are there in 34 grams of NaCl?
3.5 x 1023 particles
Which element has the highest electronegativity value, and what does electronegativity mean?
Fluorine, ability to attract electrons