Chemical Calculations

Question 1

What is an isotope

Answer 1

Atoms of the same element with different numbers of neutrons but the same number of protons

Question 2

How to calculate relative atomic mass

Answer 2

(mass X percentage)+(mass X percentage)
/ 100

Question 3

How to calculate RFM

Answer 3

Relative formula mass of any compound is the sum of the relative atomic masses

Question 4

How many atoms are in one mol of any substance

Answer 4

(6.02 x 10^23)

Question 5

What the equation triangle for mass moles and RFM

Answer 5

M g
Moles RFM (mr) or mr mol

Question 6

How can you calculate unknown mass given data and a balanced equation

Answer 6

1. Calculate the number of moles in the substance with mass given
2. Calculate the ratio
3. Use m = n x Mr to find mass

Question 7

What is the limiting re agent

Answer 7

The reactant that is all used up, setting a limit on how much product can be formed, the reactant that is left over is described as being in excess

Question 8

How do you calculate the limiting re agent

Answer 8

1. Calculate the number of moles in each substance
2. Divide by the ratio
3. The smallest number is the limiting reagent

Question 9

How can you construct balanced equations from mass data

Answer 9

1. Calculate the number of moles for each substance
2. Divide all of the moles by the smallest one
3. the numbers left can be substituted into the equation to balance it