Monitoring mass loss

Question 1

What is this method suitable for?

Answer 1

Reactions in which gas is evolved
Examples - acid + metals, acids + carbonates

Question 2

Describe a method in which we could monitor mass loss

Answer 2

Measure out 250cm3 of 1.0moldm-3 HCl into a conical flask using a measuring cylinder
Weigh by difference 10.00g of calcium carbonate into a beaker using a mass balance
Place the conical flask on the balance; zero (tare) the balance
Add the calcium carbonate and start the stop watch
Record the mass every 10 seconds using a stop watch
Plot a graph of mass (on the y axis) against time (on the x axis)
Draw tangents at t=0 and t=100 and calculate the respective gradients