2g of a mixture hydroxide and sodium chloride as impurity were dissolved in 500 cm3 of water. If 25cm3 of this solution
were neutratred by 21 cm² of 0.1mol dm3 of hydrochloric acid,
calculate the percentage of the sodium chloride impurity.
(NaoH=40,Hcl=36.5,NACl=58.5)​

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a.the mitochondria b.the nucleus c.the vacuoles d.the endoplasmic reticulum

Which of the following has wavelength longer than the wavelength of viable light? a) x rays b) gamma rays c) radios waves d) ultraviolet waves