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.

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.

The last few miles of the marathon are the most difficult for heather, her hair plastered to her head, sweat clinging to her arms, and her legs already feeling as if they had nothing left, just dead weight. after grabbing a cup of ice water, she feels the ice cubes smash against her nose as she gulps some cool refreshment and keeps on running. in these last few miles, the breeze kicks up and she finally feels some coolness against her skin. drips of sweat, once clinging to her forehead, now spill down, and heather feels more pain as the sweat flows into her eyes.which of the following is the most likely reason why the ice struck heather’s nose when she took a drink? a) water can function as a solvent. b) water can store large amounts of heat. c) water can moderate temperatures through evaporative cooling. d) the density of water decreases when it freezes. e) water has a cohesive nature.sweat remained on heather’s forehead and arms because of the a) high salt content of sweat b) cohesive nature of water c) ability of water to moderate heat d) high evaporative cooling effect of water e) ability of water to act as a solvent

What does the symbol (–hfus) indicate in a phase change?

Aweight lifter raises a 1600 n barbell to a height of 2.0 meters. how much work was done? w = fd a) 30 joules b) 3000 joules c) 320 joules d) 3200 joules