Big question for chemistry please answer.

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)

Using the results from the two previous questions: solution one: 1 x 10-4 m solution two: 1 x 10-7m the hydrogen ion concentration of these two solutions differ from each other by a factor of