Answer is c
Work out the moles of 2H2O: 1.80/ (16+1+1) = 0.1
The moles of 2H2 are the same (0.1)
The Mr of H2 is 2
So the mass needed to produce 1.80g of water is
0.1 x 2 = 0.2
Answer:
A
Explanation:
Let's illustrate this; see the attachment.
We see that Mrs. Jacobson is pushing to the right with a force of 100 N and there is another opposite force pushing with a force of 15 N. Since these are in opposite directions, we can say that the force opposite to Mrs. Jacobson is pushing the fridge -15 N to the right (instead of 15 N to the left).
The net force would then be:
100 N + (-15 N) = 85 N to the right
The answer is A.
M₁ = mass of water = 75 g
T₁ = initial temperature of water = 23.1 °C
c₁ = specific heat of water = 4.186 J/g°C
m₂ = mass of limestone = 62.6 g
T₂ = initial temperature of limestone = ?
c₂ = specific heat of limestone = 0.921 J/g°C
T = equilibrium temperature = 51.9 °C
using conservation of heat
Heat lost by limestone = heat gained by water
m₂c₂(T₂ - T) = m₁c₁(T - T₁)
inserting the values
(62.6) (0.921) (T₂ - 51.9) = (75) (4.186) (51.9 - 23.1)
T₂ = 208.73 °C
in three significant figures
T₂ = 209 °C
<span>NO2 weighs 46.005 grams per mol. There are 6.02x10^23 molecules in a mol. In the given sample of 189.5 grams, there are 4.12 mols. This means that there are 2.48x10^24 molecules of NO2 in the given sample.</span>
