Chapter 1- Review

Question 1

What is the atomic number and mass number of an element?

Answer 1

Mass number
Element
Atomic number

Mass number= molar mass (protons+neutrons)
Atomic number= number of protons

Question 2

How do you solve abundance questions for percents when given all the amu?

Answer 2

Make one percent of one isotope x and the other 1-x then:

Molar mass= amu(x) + amu (x-1)

Question 3

How do you find the empirical formula of a compound when given the percent compounds of each element?

Answer 3

Consider a 100g same so each percent is the grams then find moles then divide by least moles

Question 4

How do you find the amount of a substance in excess?

Answer 4

Find the limiting reagent and excess reagent, then subtract the moles of the excess reagent by the moles of the limiting reagent

Question 5

What is molarity (M)?

Answer 5

Moles divided by litres

1L solution = (molarity number) moles of element

Question 6

How do you solve a question that gives molarity and moles when finding litres?

Answer 6

Divide the moles by the molarity to eliminate moles and get litres

Question 7

When you’re given the molarities of two compounds that contain a similar element how do you find the molarity of that element in the compound?

Answer 7

You find the moles of the element in each compound to find the molarity of the element in each solution then add them together

Question 8

What is the dilution formula?

Answer 8

M1V1=M2V2