Mass of methanol (CH3OH) = 1.922 g
Change in Temperature (t) = 4.20°C
Heat capacity of the bomb plus water = 10.4 KJ/oC
The heat absorbed by the bomb and water is equal to the product of the heat capacity and the temperature change.
Let’s assume that no heat is lost to the surroundings. First, let’s calculate the heat changes in the calorimeter. This is calculated using the formula shown below:
qcal = Ccalt
Where, qcal = heat of reaction
Ccal = heat capacity of calorimeter
t = change in temperature of the sample
Now, let’s calculate qcal:
qcal = (10.4 kJ/°C)(4.20°C)
= 43.68 kJ
Always qsys = qcal + qrxn = 0,
qrxn = -43.68 kJ
The heat change of the reaction is - 43.68 kJ which is the heat released by the combustion of 1.922 g of CH3OH. Therefore, the conversion factor is:
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
)
i. When an acid reacts with metal, a salt and hydrogen are produced:
ii. When oxygen and metal react, metal oxide forms also known as rust
iii. metal and water produce hydrogen gas
When you ride a bicycle, several things happen that require energy and it's transformation. You pedaling the bike is transforming chemical energy, supplied by the breakdown of the food you eat, into mechanical energy to turn the pedals. The chemical energy is potential and the mechanical energy is kinetic.
Answer: -
The approximate number of atoms in a bacterium is 10¹¹
Explanation: -
We are given the mass of a bacterium is 10⁻¹⁵ kg.
We are told that the mass of a hydrogen atom is 10⁻²⁷ kg.
Finally we learn that the average mass of an atom of the bacterium is ten times the mass of a hydrogen atom.
Mass of an atom of bacterium = 10 x mass of hydrogen atom
= 10 x 10⁻²⁷ kg.
= 10⁻²⁶ kg.
Thus the number of atoms in a bacterium = 
= 
= 10¹¹
