The balanced reaction is 3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
).
<u>Explanation</u>:
A chemical equation is said to be balanced when the total number of atoms present on the reactants side is equal to the total number of atoms present on the product side.
The unbalanced chemical equation is as follows,
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
To balance this equation, you need to look at how many atoms of each element are present on each side of the chemical equation.
Calcium has 1 atom on the reactant and 3 on the products side. To balance the reaction we need to multiply the calcium atom by 3 on the reactants side.
3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
Now Nitrogen has a coefficient of 2 on both sides of the reaction. Hence the balanced chemical equation will thus be
3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
Answer:
<u><em>The correct option is C) the moon takes the same time to rotate and revolve.</em></u>
Explanation:
Scientific experiments have concluded that it takes approximately 23 days for the moon to rotate and also it takes the same duration for the moon to revolve around the Earth. Due to this consistency, the moon appears to be still.
<em>Such synchronization results in the same face of the moon to be directed towards the Earth. Hence, the same craters of the moon will be observed by the scientist every day.</em>
<em></em>
Other options, like option D, is not correct because there will be craters on the other side of the moon too. But as we see the same side of the moon, hence we cannot see the craters present on the other side of the moon.
Answer: True
Explanation:
The matter exists as solid, liquid or gas. These are called the states of matter. The change of matter from one state to another can be achieved by heating or cooling.
The solid state can be converted into liquid state by providing heat to solid. The heat will make the particles move farther, resulting into liquid state.
Similarly when liquid state is provided heat, it changes to gaseous state. The heat will make the particles move much more faster.
Thus the statement that when heat flows to an object, it can change states is True.
Answer:
C
Explanation:
When something is chemical it is warped into a completely new substance and when coal is burned it is new so it is definitely C.
Answer : The internal energy change is -2805.8 kJ/mol
Explanation :
First we have to calculate the heat gained by the calorimeter.
where,
q = heat gained = ?
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 fructose = 
Therefore, the enthalpy change during the reaction is -2805.8 kJ/mole
Now we have to calculate the internal energy change for the combustion of 1.501 g of fructose.
Formula used :
or,
where,
= change in enthalpy = 
= change in internal energy = ?
= change in moles = 0 (from the reaction)
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get:
Therefore, the internal energy change is -2805.8 kJ/mol
