Answer:
The correct option is: a. Photosphere
Explanation:
Sun is the brightest star in the sky of our planet Earth and the principle component of the Solar System. It is a <u>gaseous object</u> that is made up of hot plasma and contributes 99.86% to the total mass of our Solar System.
<u>The Sun does not have a clearly defined surface.</u> The <u>visible surface of the Sun is known as the Photosphere</u>, which is the deepest visible portion of the Sun.
Answer:
Avogadro's number is 6.022×1023 molecules. With Avogadro's number, scientists can discuss and compare very large numbers, which is useful because substances in everyday quantities contain very large numbers of atoms and molecules.
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It would be 12.4 moles of HCL because you multiply 6.2 by how many moles of HCL in te equation then divide it by how many moles of h2 in the equation so you multiple 6.2 by 2 moles because there’s two moles of HCL which gives you 12.4 then you divide it by one because in the equation there is only 1 mole of H2
First a balanced reaction equation must be established:

→

Now if mass of aluminum = 145 g
the moles of aluminum = (MASS) ÷ (MOLAR MASS) = 145 g ÷ 30 g/mol
= 4.83 mols
Now the mole ratio of Al : O₂ based on the equation is 4 : 3
[
4Al +
3 O₂ → 2 Al₂O₃]
∴ if moles of Al = 4.83 moles
then moles of O₂ = (4.83 mol ÷ 4) × 3
=
3.63 mol (to 2 sig. fig.)
Thus it can be concluded that
3.63 moles of oxygen is needed to react completely with 145 g of aluminum.
Answer:
0.02 tons of NO produced when 4 tons of coal is burned
Explanation:
From the given,
Chemical formula of coal = 
Molecular mass of coal = 
Let’s calculate the mass of nitrogen in coal


Amount of coal burnt = 4tons
Amount of NO produced by burning 4tons = 
This nitrogen is converted into NO by reacting with atmospheric oxygen.