"You may find what you seek, or you might not" Is an excellent quote that might help.
Answer:
4.6 × 10²³ molecules:
Step-by-step solution
You will need a balanced equation with masses, moles, and molar masses, so let's gather the information in one place:
M_r: 22.99
2Na + 2H₂O ⟶ 2NaOH + H₂
m/g: 35
1. Calculate the <em>moles of Na
</em>
Moles of Na = 35 g Na × (1 mol Na/22.99 g Na)
Moles of Na = 1.52 mol Na
2. Calculate the <em>moles of H₂
</em>
Moles of H₂ = 1.52 mol Na × (1 mol H₂/2 mol Na)
Moles of H₂= 0.761 mol H₂
3. Calculate the molecules of H₂
6.022 × 10²³ molecules H₂ = 1 mol H₂
Molecules of H₂ = 0.761 × (6.022 × 10²³
/1)
Molecules of H₂ = 4.6 × 10²³ molecules H₂
The reaction forms 4.6 × 10²³ molecules of H₂.
Answer:Valence Shell
Explanation: The Valence Shell is the outermost orbital of an atom. The Valence Shell electrons are used in making chemical bonds and are the reason the atom has its physical and chemical properties.
Answer: -
2 x 10 ²⁴ atoms of Ag rounded off to 1 significant figures.
Explanation: -
Mass of Cu = 100 g
Molar mass of Cu = 63.55 g / mol
Number of moles of Cu = 100 g / (63.55 g/mol)
= 1.574 mol of Cu
The balanced chemical equation for the reaction is
Cu + 2AgNO₃ → Cu(NO₃)₂ + 2 Ag
From the balanced chemical equation we see
1 mol of Cu gives 2 moles of Ag
1.574 mol of Cu gives ![\frac{2 moles of Ag x .574 mol of Cu}{1 mo of Cu}](https://tex.z-dn.net/?f=%20%5Cfrac%7B2%20moles%20of%20Ag%20x%20.574%20mol%20of%20Cu%7D%7B1%20mo%20of%20Cu%7D%20%20)
= 3.148 mol of Ag
1 mole of Ag has 6.02 x 10 ²³ atoms of Ag according to Avogadro's Law.
3.148 mol of Ag has ![\frac{6.02 x 10 ²³ atoms of Ag x 3.148 mol of Ag}{1 mol of Ag}](https://tex.z-dn.net/?f=%20%5Cfrac%7B6.02%20x%2010%20%C2%B2%C2%B3%20atoms%20of%20Ag%20x%203.148%20mol%20of%20Ag%7D%7B1%20mol%20of%20Ag%7D%20%20)
= 18.95 x 10²³ atoms of Ag
= 2 x 10 ²⁴ atoms of Ag rounded off to 1 significant figures.