Which of the following substances will cause the least temperature change if the same amount of each substance is added to 1.0 kg of water? k3po4 cuso4 ch4oh mgcl2

will cause least temperature change

Explanation:

Change in temperature is proportional to van't hoff factor (i) as both concentration of solute and solvent (water) remains same.

Now, i depends on number of ions produced from dissociation of one molecule of solute in solution

For non-electrolyte, i is equal to 1 whereas for strong electrolytes

are strong electrolytes i.e. fully dissociated into solution. But is a non-electrolyte i.e. does not dissociate into solution

So change in temperature will be least for

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e