Question

In chemistry lab the students started with 150 g of a substance. They were to heat the substance and reweigh it after 5, 10 ,15, and 20 minutes had passed and record the weights. The students recorded the following data: minutes passedgrams left5149.6510123.9315100.222089.96 If the students round each weight measurement to the nearest tenth, what is the approximate total change in weight of the substance after 20 minutes?

Answer 1

At first the substance has the weight 150 g.

At 20 minutes the weight of the substance is 89.96

Round it to nearest tenth, we get

90.

Hence the approximate change in weight after 20 minutes is

150-90=60 g