Ca + 2h2o --> ca(oh)2 + h2
40g of ca is mixed with 100g of water. calculate mass of solution left after reaction is complete.

Explanation:

Ca(s) + 2H₂O(ℓ) ⟶ Ca(OH)₂(s) + H₂(g)

Mass of reactants = mass of products

You have 140 g of reactants, so you should get 140 g of products.

The calcium hydroxide and the left-over water will remain in the beaker, but the hydrogen will escape.

According to  the equation, 1 mol (40 g) of Ca produces 1 mol (2.0 g) of hydrogen.

Mass of suspension + mass of hydrogen = 140    g

                           Less mass of hydrogen =    2.0 g

                                 Mass of suspension = 138    g

-be a crystalline solid

- be soluble in water

-conduct electricity

hope this : )

i'm assuming that the correct answer is indeed the first one/ "a"..