G10 Unit 26 Chemical Reactions and Chemical Change

Question 1

a substance changes physical appearance but its composition remains the same

Answer 1

physical change

Question 2

involves a change in the identity of the original substance

Answer 2

chemical change

Question 3

refer to processes in which a new substance is made from the rearrangement of atoms in the molecules or compounds

Answer 3

Chemical reactions

Question 4

insoluble solid formed when two solutions are mixed together.
Soap, which contains stearate, forms an insoluble solid (calcium stearate or “soap
scum”) with magnesium and calcium ions present in the Epsom salt solution.

Answer 4

precipitate

Question 5

Indicators of Chemical Changes

Answer 5

Changes in color, texture, or other observable characteristics

Formation of precipitates

Effervescence or bubbling

Question 6

bubble formation in a solution

Answer 6

Effervescence

Question 7

energy, in general, is absorbed the process is said to be _

Answer 7

endergonic

Question 8

when energy is released the process is said to be _

Answer 8

exergonic

Question 9

if it absorbs heat

Answer 9

endothermic

Question 10

if it releases heat

Answer 10

exothermic