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lutik1710 [3]
2 years ago
5

The chemical standard for the quantity of a mole is based on which substance? a.hydrogen-1 b.helium-2 c.oxygen-16 d.carbon-12

Chemistry
1 answer:
jekas [21]2 years ago
5 0
D.carbon-12 is the answer.......
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Balance the chemical equation. ___Mg + ___Fe2O^3 -> ___MgO + ___Fe
VMariaS [17]

Answer:

3Mg + Fe₂O₃ → 3MgO + 2Fe.

Explanation:

  • To balance the equation, you should apply the law of conservation of mass for the equations.
  • The law of conservation of mass states that the no. of each atom is equal in both sides (reactants and products).
  • The balanced equation is:

<em>3Mg + Fe₂O₃ → 3MgO + 2Fe.</em>

<em></em>

That 3.0 mole of Mg react with 1.0 mole of Fe₂O₃ to produce 3.0 moles of MgO and 2.0 moles of Fe.

  • The no. of all atoms is the same in both of reactants and products side.

Mg (3), Fe (2), and O (3).

8 0
3 years ago
you need 16.66ml (+-0.01) of 53.4 (+-0.4)wt% of NaOH with a density of 1.52 (+-0.01)g/mL to prepare 2.00L of 0.169M of NaOH. Wha
pashok25 [27]

Answer:

The absolute uncertainty is approximately 1.69 × 10⁻³

Explanation:

The volume needed for NaOH needed to make the solution = 16.66 ml

The wt% of the added NaOH = 53.4 wt%

The volume of the NaOH to be prepared = 2.00 L

The concentration of the NaOH to be prepared = 0.169 M

The molar mass of NaOH = 39.997 g/mol

Therefore, 100 g of sample contains 53.4 g of NaOH

The mass of the sample = 16.66 × 1.52 = 25.3232 g

The mass of NaOH in the sample = 0.534 × 25.3232 = 13.5225888 g ≈ 13.52 g

Therefore;

The number of moles of NaOH = 13.52/39.9971 = 0.3381 moles

Therefore, we have 0.3381 moles in 2.00L solution, which gives;

The number of moles per liter = 0.3881/2 = 0.169045 moles/liter

The molarity ≈ 0.169 M

The absolute uncertainty, u(c) is given as follows;

u(c) = \sqrt{ \left (\dfrac{0.01}{16.66} \right )^2 + \left ( \dfrac{0.4}{53.4} \right )^2 + \left ( \dfrac{0.01}{1.52} \right )^2 }   \times 0.169 \approx 1.69 \times 10^{-3}

The absolute uncertainty, u(c) ≈ 1.69 × 10⁻³.

3 0
2 years ago
STATES THAT FOR AN ATOM IN THE GROUND STATE, THE NUMBER OF UNPAIRED ELECTRONS IS THE MAXIMUM POSSIBLE AND THESE UNPAIRED ELECTRO
BartSMP [9]

Answer:

Hund's rule

Explanation:

Hund's rule  states that for an atom in the ground state, the number of unpaired electrons is the maximum possible and these unpaired electrons have the same spin.

I will clearly illustrate this using the ground state of the nitrogen atom. Nitrogen atom contains seven electrons. Its electronic configuration is; 1s2 2s2 2px1 2py1 2pz1.

Notice that the number of unpaired electrons in this configuration is maximum and they are all expected to possess the same spin in accordance with Hund's rule .

4 0
2 years ago
I am the life cycle that contains tiny undeveloped plants,
LuckyWell [14K]
The water cycle regardless if it is in a lake, our bodies, food, or underground.
7 0
2 years ago
Which of the following are sources of revenue for media companies? A. Direct sales to producers B.advertising and subscriptions
Fed [463]

Answer:

c

Explanation:

5 0
3 years ago
Read 2 more answers
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