This is a percentage composition by mass problem.

what is the approximate percent by mass of the water in the hydrated salt?

select one:
a. 98%
b. 88%
c. 2.5%
d. 12%

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?

What is the area in square meters of 448 g ai foil that has a thickness of 23921 nm? the density is 2.70 g/cm

When the mercury level in a barometer decreases that atmospheric pressure has