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.
Density = mass / Volume 0.856 g/cm3 = x / 30 cm3(0.856)(30) = xx = 25.68 grams
The amount of heat required to melt 15.0 grams of ice at 0.0º C is<u> 4950 J.</u>
<h3>What is the amount of heat required to melt 15.0 grams of ice at 0.0º C?</h3>
The amount of heat required to melt 15.0 grams of ice at 0.0º C is calculated from the formula given below:
Amount of heat = mass * latent heat of fusion of ice
The latent heat of fusion is the amount of heat required to convert a unit mass of ice at 0.0º C to water at 0.0º C
The latent heat of fusion of ice is 330J/g
mass of ice = 15.0 g
Amount of heat required = 15.0 g * 330 J/g
Amount of heat required = 4950 J
Learn more about latent heat of fusion at: brainly.com/question/87248
#SPJ1
