What mass of potassium must react with water to produce 50.0 grams of h2?

The reaction between water and a metal is vigorous and  produces a metal hydroxide and hydrogen gas. First we write a balanced equation for the reaction.

First we find the number of moles of using the 50 g mass and the molar mass of dihydrogen 2.01grams.

Then we use the moles of hydrogen and molar mass of K, 39.01 to find the mass of potassium needed to react.

1941.14 g potassium should react with water.

the answer is 1 i believe

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.