Divide 6.25/8.25 = ?? There are three significant figures in each; therefore, you are allowed three in the final answer by the multiplication/division rules.
#2. I can interpret the question two ways. IF I KNOW, because someone told me, that EACH raisin had a mass of 1.011 grams, then I wouldn't need a balance (I don't call them scales). I would simply multiply 1.011 x 10 = 10.11 grams.
BUT, if only one raisin has a mass of 1.011 g (and I know that's exact), then I add
1.01 +
1.01 +
1.01 +
etc 9 times and the answer is
9.09 grams for the 9 raisins. Then if I add
9.09 + (the 1.01 added 9 times and accurate to the hundredths place. +
1.011 (accurate to the thousandths place.
------
10.101 grams
In addition/subtraction, the number of s.f. is determined by the digits to the right of the decimal point. In this case, the accuracy is to the hundredths place; therefore, the total should be rounded to 10.10 (dropping the last 1 of the 10.101).
Check my thinking. I think the problem was meant to be interpreted the latter way.
#1) Complete the following calculation by providing the correctly rounded answer in SI Units: 6.25 g divided by 8.25 g/mol
#2)You are using a scale that has an accuracy of 0.01g. Suppose you have been told that one raisin has a mass of 1.011 g and you measure the other 9 raisins at a mass of 1.01 g each. What would be the mass of 10 raisins? State your answer to the correct number of significant digits.
2 answers
Thank-you, That's what I thought to for #2...