Exam 1 math Equations

Converting from decimal to scientific notation: moving the decimal to right is it positive or negative?

Moving the decimal to left is it positive or negative?

Right- Positive

Left- Negative

When you multiply exponential terms do you add or subtract?

Add

When you divide exponential terms do you add or subtract?

Substract

In unit conversions when your going from a smaller to a bigger unit. The number should be small or bigger, so then you should divide or subtract it?

The number should be smaller so you should divide.

In unit conversions when your going from a bigger to a smaller unit. The number should be small or bigger, so then you should divide or multiply it?

The number should be bigger so multiply.

What is the density forrmula

D= m / v

What is the formula to convert from Celsius to kelvin?

C degrees + 273.15 K

What is the formula to convert from kelvin to celisus?

K - 273.15 K

Writing chemical symbol notation

How to calculate average atomic mass.

1. Convert percentages into decimals

2. Multiply decimals by corresponding amu

3. Add all

Writing empirical formulas

Simpilfy

Formula of an ionic compound gives what?

Gives the smallest possible integer number of ions in the substance.

Naming binary ionic compounds w/ fixed charge.

1. Name metal first

2. If monoatomic add “-ide”

3. If polyatomic used the name of the anion

Naming binary ionic compounds w/ more than one charge.

1. Name metal first

2. Specify charge of the metal cation with a roman numeral in the parentheses

3. If monatomic anion, add “-ide” to the root name of the element name

4. If polyatomic anion, use the name of the anion

How to go from grams to moles?

Divide the given grams by the total grams of the actual compound.

How to go from Moles to Grams?

Multiply the given grams by the total grams of the actual compound.

How to solve for molecular mass of a compound.

Sum of the atomic masses in a molecule.

How to solve for formula mass of a ionic compound.

Same as solving for molecular mass.

How to solve for percent composition

How to determine the empricial formula of the compound using percent composition

1. Must assume you have 100 g of the compound first

2. Calc all the percent comps

3. Divide all percent comp answers by the smallest percent comp answer

4. Multiply by factor that will get decimals to a whole #

How to calculate limiting reagent problems? How to find excess?

1. Do the stochiometry problem for both grams given to get the grams of the given COMPOUND

2. Find out the limiting regeant

3. To find excess: Take limiting reagent and convert it to the other reactant in the equation

4. Subtract the given # of grams of the other reactant by the answer you got finding the excess.

Percent yield formula.

How to find the theorectical yield if not given?

The theorectical yield will be answer you got when you tried to find the product amount when finding the limiting reactant.

How to determine the molecular formula of the compound using percent composition. Whats the extra step you have to take?

1. Must assume you have 100 g of the compound first

2. Calc all the percent comps

3. Divide all percent comp answers by the smallest percent comp answer

4. Multiply by factor that will get decimals to a whole #

5. Find the ratio of the molar masses by dividing the given mass in the problem by the total mass of the compound.

6. Multiply empirical formula by that answer.

How to use density formula to get volume?

v= m/d

How use to density formula to get mass?

m= D x V