Please, observe that it is not right to say that a substance content heat.
Heat is not something that a body or substance content. Heat is the transmission of energy due to difference of temperatures.
An endothermic reactions is that where the reactants abosorb energy from the surroundings to occur. The products, then, will be higher in energy than the reactants while the surroundings get colder.
Answer: 3.75 M
Explanation:
400 mL = 0.4 L
NaOH has a molar mass of around 40 g/mol.
= 1.5 moles
Molarity = 
= 3.75 M
Answer:
ok and thank you for free point
Answer:
It would have to be around 9.8 volume
Explanation:
3Si + 2N2 --> Si3N4 (as given)
n(Si) = m/MM = 38.25/28.085 = 1.3619 mol
n(N2) = 14.33/2*14.007 = 0.5115 mol
Therefore, N2 is limiting and Si is in excess
The molar ratio of 2N2:Si3N4 is 2:1
So, 0.0575 mol of silicon nitride is formed (dividing 0.5115 by 2)
m of silicon nitride= n*mm = 0.0575*140.283 = 8.06627... g
= 8.066g (4 significant figures)
(hopefully it is right, but double check in case i did something wrong) :)
