Ca(OH)2 -------> CaO + H2O
ratio is 1 : 1
CaO Mr= 56g
15/56 = 0.268 mol (mols of CaO in 15g)
Ca(OH)2 Mr= 74g
0.268x74= 19.83g (required amount of Cash(OH)2)
Answer : The enthalpy change during the reaction is -6.48 kJ/mole
Explanation :
First we have to calculate the heat gained by the reaction.
where,
q = heat gained = ?
m = mass of water = 100 g
c = specific heat =
= final temperature =
= initial temperature =
Now put all the given values in the above formula, we get:
Now we have to calculate the enthalpy change during the reaction.
where,
= enthalpy change = ?
q = heat gained = 23.4 kJ
n = number of moles barium chloride =
Therefore, the enthalpy change during the reaction is -6.48 kJ/mole
To get the theoretical yield of ammonia NH3:
first, we should have the balanced equation of the reaction:
3H2(g) + N2(g) → 2NH3(g)
Second, we start to convert mass to moles
moles of N2 = N2 mass / N2 molar mass
= 200 / 28 = 7.14 moles
third, we start to compare the molar ratio from the balanced equation between N2 & NH3 we will find that N2: NH3 = 1:2 so when we use every mole of N2 we will get 2 times of that mole of NH3 so,
moles of NH3 = 7.14 * 2 = 14.28 moles
finally, we convert the moles of NH3 to mass again to get the mass of ammonia:
mass of NH3 = no.moles * molar mass of ammonia
= 14.28 * 17 = 242.76 g
It can only do that when one of the components of the mixture is a magnetic
material.
When you have that situation, you pass the magnet over the mixture ... shaking
the mixture if it's a dry mixture of powders or pieces ... and the magnetic part of
the mixture moves toward the magnet, while the nonmagnetic parts of the mixture
couldn't care less about the magnet and they just stay where they are.
Answer:
CCl₄, because it is the heaviest compound.
Explanation:
When a liquid is in a closed container, evaporation occurs, in what the molecules with the highest kinetic energy can scape of the liquid. The vapor that was formed does pressure on the liquid that remains, and when both phases stay in equilibrium the pressure is called vapor pressure.
We can notice that the vapor pressure is a measure of the volatility of a liquid. Substances with higher vapor pressure are more volatile. The volatility, however, depends on the nature of the forces in the compound and on the molar mass of it.
For the substances given, they are all covalent compounds and have dipole-induced-dipole-induced bonds between the molecules (because they are nonpolar). So, the lowest vapor pressure is in the heaviest compound, which is the most substituted: CCl₄.