Answer:
B.) 36.0 grams
Explanation:
To find the mass of water, you need to (1) convert grams H₂ to moles (using the molar mass), then (2) convert moles H₂ to moles H₂O (using mole-to-mole ratio from reaction coefficients), and then (3) convert moles H₂O to grams (using the molar mass). It is important to arrange the conversions in a way that allows for the cancellation of units.
Molar Mass (H₂): 2(1.008 g/mol)
Molar Mass (H₂): 2.016 g/mol
Molar Mass (H₂O): 2(1.008 g/mol) + 15.998 g/mol
Molar Mass (H₂O): 18.014 g/mol
2 H₂ + O₂ -----> 2 H₂O
^ ^
4.0 g H₂ 1 mole 2 moles H₂O 18.014 g
--------------- x ---------------- x ------------------------ x --------------- = 36 g H₂O
2.016 g 2 moles H₂ 1 mole
The answer is the third one
A fusion reaction takes place between carbon and another element. Neutrons are released, and a different element is formed. The different element is Lighter than helium.
Surface tension is the result of water molecules pulling inward with a strong attractive force.
The attractive force brings the molecules on the surface of the water close together.
The attractive force causes the surface of the water to be drawn toward the water molecules beneath the surface. <span>
Since there are no water molecules above the surface, there are uneven forces. This causes surface tension, allowing the coin to float on the water’s surface.</span>
Molar mass Na = 23.0 g/mol
1 mol ---- 23.0 g
n mol ---- 69 g
n = 69 / 23.0
n = 3.0 moles
1 mole -------- 6.02x10²³ molecules
3.0 moles ---- ?
3.0 * 6.02x10²³ / 1
= 1.806x10²⁴ molecules
hope this helps!
