CH 1-2
Boiling water is an example of a chemical or physical change.
Let's get physical!
How many sig figs is 3,100
2
Platinum (II) chloride
How many molecules are in 51,000 moles?
3.1 x 1028 molecules
Compound, mixture, or pure substance?
N2 and O2
Mixture
Round 22.998 to 4 sig figs
23.00
Write the isotope hyphen notation for oxygen if its mass number is 18.
Oxygen - 18
What is the percent composition of Mg(OH)2?
% Mg = 41.68
% O = 54.86
% H = 3.456
Distilled water is
Pure water!!!
How do you measure something?
Write down the numbers that are certain, then add 1 more digit that is uncertain.
Which scientist discovered the electron?
The one and only J.J. Thomson
The empirical formula of a compound is CH2. Its molecular mass is 70.00 g/mole. What is the molecular formula?
C5H10
What are the 4 steps of the scientific method?
1. Make observations, 2. formulate a hypothesis, 3. perform experiments and make observations, 4. draw conclusions.
Compare accuracy and precision.
Accurate is how close a single measurement is to the actual value.
Precision is how close several measurements are to each other.
What is the formula of aluminum sulfate?
Al2(SO4)3
How many atoms are in 41 g of Mg?
1.0 x 1024 atoms
The 4 indicators of a chemical change
1. release of a gas
2. production of light/heat
3. unexpected color change
4. formation of a precipitate (solid)
What is the density of Ms. Cumpston's favorite Chobani creamer if it weighs 200 g with a volume of 710 mL.
0.3 g/mL
What are the differences between type I, type II, and type III and how do you name them?
Type I contains a metal with 1 charge.
- Full name of metal with anion -ide name
Type II contains a metal with more than 1 charge.
- Full name of metal (roman numeral charge) with anion -ide name
Type III contains only nonmetals.
- Prefixes are used to indicate how many are in the formula
CHEM 3: Write, then balance the equation.
When aqueous barium chloride and aqueous sodium carbonate are mixed, they produce solid barium carbonate and aqueous sodium chloride.
CHEM 4: Write the equation and predict the products for the reaction. Then balance!
Aqueous lithium phosphate and aqueous barium chloride -->
CHEM 3:
BaCl2 (aq) + Na2CO3 (aq) --> BaCO3 (s) + 2 NaCl (aq)
CHEM 4:
2 Li3PO4 (aq) + 3 BaCl2 (aq) --> 6 LiCl (aq) + Ba3(PO4)2 (s)