Answer:
1.44 x 10²⁵ ions of Na⁺
Explanation:
Given parameters:
Mass of NaCl = 1.4kg = 1400g
Unknown:
Number of ions of sodium = ?
Solution:
The compound NaCl in ionic form can be written as;
NaCl → Na⁺ + Cl⁻
In 1 mole of NaCl we have 1 mole of sodium ions
Now, let us find the number of moles in NaCl;
Number of moles =
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Number of moles =
= 23.93mol
So;
Since 1 mole of NaCl gives 1 mole of Na⁺
In 23.93 mole of NaCl will give 23.93 mole of Na⁺
1 mole of a substance = 6.02 x 10²³ ions of a substance
23.93 mole of a substance = 6.02 x 10²³ x 23.93
= 1.44 x 10²⁵ ions of Na⁺
Molarity is given as,
Molarity = Moles / Volume of Solution ----- (1)
Also, Moles is given as,
Moles = Mass / M.mass
Substituting value of moles in eq. 1,
Molarity = Mass / M.mass × Volume
Solving for Mass,
Mass = Molarity × M.mass × Volume ---- (2)
Data Given;
Molarity = 2.8 mol.L⁻¹
M.mass = 101.5 g.mol⁻¹
Volume = 1 L (I have assumed it because it is not given)
Putting values in eq. 2,
Mass = 2.8 mol.L⁻¹ × 101.5 g.mol⁻¹ × 1 L
Mass = 284.2 g of CuF₂
Rotting vegetables is a chemical change I think.
The answer to this question would be A. Energy is released.
When a chemical bond is a form, the bond will either suck up energy or produce energy. So, to be precise the energy is not always released but also can be absorbed. In this case, the energy released number will be a minus.
Options B and C is definitely wrong since the bond is formed by an electron, it won't affects neutron/proton.
Option D might be true since the product is made of 2 or more atoms then it would seem larger. But the size of the actual atom won't be increased.