In an experiment, sulfuric acid reacted with different volumes of sodium thiosulfate in water. A yellow precipitate was formed during the reaction. A cross drawn at the base of each flask became gradually invisible due the formation of this yellow precipitate. The time taken for the cross to become invisible was recorded. A partial record of the experiment is shown.

Experimental Record

Flask Volume of

H2SO4 Volume of

Sodium Thiosulfate Volume of

Water Time

1 5 mL 50 mL 0 mL 19 seconds

2 5 mL 40 mL 10 mL

3 5 mL 30 mL 20 mL

4 5 mL 20 mL 30 mL

Based on your knowledge of factors that affect the rates of chemical reactions, predict the trend in the last column of the experimental record. Use complete sentences to explain the trend you predicted. You do not have to determine exact values for time; just describe the trend you would expect (increase or decrease) and why it occurs.