How many significant figures are in the following measurement: 68.99 mL

Count how many significant figures are in a number, and find which digits are significant. You can use this calculator for significant figures practice: Test your ability to find how many significant figures are in a number.Enter whole numbers, real numbers, scientific notation or e notation. Example inputs are, 3500, 35.0056, 3.5 x 10^3 and 3.5e3.

Explanation:

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o