I think mm is not a unit of pressure
Answer:
10.60 grams of silane gas are formed.
Explanation:
From the reaction:
Mg₂Si(s) + 4H₂O(l) → 2Mg(OH)₂(aq) + SiH₄(g)
We know that the limiting reactant is Mg₂Si, so to find the mass of SiH₄ formed we need to calculate the number of moles of Mg₂Si:

Where:
m: is the mass of Mg₂Si = 25.0 g
M: is the molar mass of Mg₂Si = 76.69 g/mol

Now, the stoichiometric relation between Mg₂Si and SiH₄ is 1:1 so:

Finally, the mass of SiH₄ is:

Therefore, 10.60 grams of silane gas are formed.
I hope it helps you!
Answer:
Mass of 1 mole of copper is 63.83 g.
0.03916 moles of copper atoms have a mass equal to the 2.5 grams of copper penny.
Explanation:
Mass of 1 copper atom,m = 

Mass of 1 mole of copper :
= 
Mass of 1 mole of copper = 63.83 g
Mass of copper penny = 2.5 g
Atomic mass of copper = 63.83 g/mol
Moles of copper in 2.5 g of copper penny:

0.03916 moles of copper atoms have a mass equal to the 2.5 grams of copper penny.
Answer:
BRAINLIEST?
Explanation:
Ammonia is a typical weak base. Ammonia itself obviously doesn't contain hydroxide ions, but it reacts with water to produce ammonium ions and hydroxide ions. My findings said that ammonia is a weak base, potassium hydroxide is a strong base, vinegar is a weak acid and ethyl alcohol is a weak acid.
Vinegar and ethyl alcohol are eliminated as they are acids. The question is on bases.... Potassium hydroxide is a strong base. So we are left with ammonia, being a weak base.
A is your answer