Answer : The reagent present in excess and remains unreacted is, 
Solution : Given,
Moles of
= 3.00 mole
Moles of
= 2.00 mole
Excess reagent : It is defined as the reactants not completely used up in the reaction.
Limiting reagent : It is defined as the reactants completely used up in the reaction.
Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,

From the balanced reaction we conclude that
As, 2 moles of
react with 1 mole of 
So, 3.00 moles of
react with
moles of 
From this we conclude that,
is an excess reagent because the given moles are greater than the required moles and
is a limiting reagent and it limits the formation of product.
Hence, the reagent present in excess and remains unreacted is, 
Answer:
B. Water will freeze
<em>because</em><em> </em><em>the</em><em> </em><em>latent</em><em> </em><em>heat</em><em> </em><em>of</em><em> </em><em>vapourization</em><em> </em><em>decreases</em><em>.</em>
They have a mass for the particles
There are no totally elastic collisions
There are intermolecular forces
Answer:
About 0.652
Explanation:
Because the reaction is balanced, we can go straight to the next step. The molar mass of potassium is about 39.098, while the molar mass of hydrogen gas is 2 and the molar mass of water is 18. Therefore, 25.5g of potassium would be about 0.652 moles, and 220 grams of water would be about 12.222 moles, making potassium the limiting reactant. Since there is a single unit of each compound on both sides of the equation, there would be an equal amount of moles of potassium and hydrogen, and therefore about 0.652 moles of hydrogen gas would be produced. Hope this helps!