Question

U 0.32301 L V.324 5. Express the results of the following equations to the correct number of significant figures (assume all numbers are measurements) : a) 13.42 g - 5.395 g = 8.025 g b) 3.4 g +0.02 g + 1.31 g = 4.73 g c) 0.876 g/(0.1266 cm x 50.0 cm * 1.00 cm) = 0.1383886 g/cm'=_ d) 19.56 mL x 0.096 g/mL = 1.87776 g =

Answer 1

Your answer cannot be more precise than the least precise measurement appearing in the expression.  The following rule applies for addion and subtraction : The least number of significant figures in any number of the expression determines the number of significant figures in the answer.In expression a least number of significant figures are 4. So there will be 4 significant figures in answer.

Answer is 8.025 g

Similarly answer for b is 4.7

In c first calculate the lowest uncertainity by dividing 1 with largest number after removing the decimal.  Here 1/1266 = 0.00078988942. The first non zero digit appears at fourth position. So there will be 4 significant figures in the answer.

Answer is 0.1384 (after rounding off)

In d lowest uncertainty in expression is up-to three significant figure. So answer is 1.88 (after rounding off)