Formula units in 450 g of
is 1.93 × 10²⁴ formula units.
<u>Explanation:</u>
First we have to find the number of moles in the given mass by dividing the mass by its molar mass as,

Now, we have to multiply the number of moles of Na₂SO₄ by the Avogadro's number, 6.022 × 10²³ formula units/mol, so we will get the number of formula units present in the given mass of the compound.
3.2 mol × 6.022 × 10²³ = 1.93 × 10²⁴ formula units.
So, 1.93 × 10²⁴ formula units is present in 450g of Na₂SO₄.
<span>Answer:
Iron triad are used in the process to create steel and other metal mixtures.
Coinage Metals are used for much more than just coins, and many other elements besides these are made into coins.</span>
Answer: pH of the solution is 12
Explanation:
NaOH —> Na+ + OH-
NaOH = 0.01M
Na+ = 0.01M
OH- = 0.01M
pOH = —log [OH-] = —log [0.01]
pOH = 2
pH + pOH = 14
pH = 14 — pOH = 14 — 2 = 12
pH = 12
1) - it can become a theory if the hypothesis is <span>tested extensively and competing hypotheses are eliminated - other options are not enough
2) This is a hypothesis. A theory is basically almost an established truth, which can still be changed with new data, but which as far as we know is true.</span>
Explanation:
The number acquired by an element after the lose or gain of an electron is called oxidation number.
For example, 
Here, oxidation number of Fe(s) is 0 and Fe in
is +3.
Oxidation number of O in
is 0 as it is present in its elemental state.
The oxidation number of O in
is calculated as follows.

Hence, oxidation number of O in
is -2.
- The loss of electrons by an element or substance is called oxidation. Here, electrons are being lost by Fe(s) as an increase in oxidation state is occurring. So, Fe(s) is oxidized.
- The gain of electrons by an element or substance is called reduction. Here, electrons are being added to
as a decrease in its oxidation state is occurring. So,
is reduced.
- An element or compound which is being reduced is called oxidizing agent. Here,
is the oxidizing agent.
- An element or compound which is being oxidized is called reducing agent. Here, Fe(s) is the reducing agent.