Answer
Energy = 3135 J
Explanation
<em>Given:</em>
Mass of water = 12.5 g
Final temperature = 72 C
Initial temperature = 12 C
Specific heat of water = 4.18 J/g C
<em>Required:</em> Energy
Solution
Q = m x Cp x ΔT
where Q is heat absorbed or released
m is the mass
Cp is the specific heat capacity
ΔT = final temperature - initial temperature
Q = 12.5 g x 4.18 J/gC x (72 - 12 C)
Q = 3135 J
149 g of cobalt are present in 1.52 x
atoms of cobalt.
<u>Explanation</u>:
One mole of an atom is equal to the Avagadro number of the atom.

The number of atoms per mol is divided by the given atoms of Cobalt.
=
= 2.52 mol of Co
To covert, the moles into grams multiply the mole value by its molar mass
The Molar mass of Cobalt is 58.93
= 2.52
58.93
= 149 g.
We use the given masses of the reactants to calculate the moles of Mn and Cl. Empirical formula represents the simplest mole ratio of atoms present in a compound.
Moles of Mn = 
Moles of Cl =
= 0.710 mol Cl
Simplest mole ratio: 
So the empirical formula is 
Answer:
A
Explanation:
Butane I think, if right pls mark brainliest.
Answer:
- 122.58 kJ
Solution:
According to following equation,
<span>2 Al + 3 Cl</span>₂ <span>→ 2 AlCl</span>₃ <span> δH</span>°<span> = -1408.4 kJ
</span>
When,
54 g (2 mole) Al on reaction releases = <span>1408.4 kJ heat
So,
4.70 g of Al will release = X kJ of Heat
Solving for X,
X = (4.70 g </span>× 1408.4 kJ) ÷ 54 g
X = - 122.58 kJ