Answer:
Explanation:
n CaCO3 = mass / m.wt
= 500 /( 40 + 12 + 16x 3)
= 5 mole
n CaO = 5 moles ( from the balanced equation we have 1:1 moles )
mass of CaO = nCaO X m.wt
5 x( 40 +16 )
= 280 grams
Answer:
339kJ
Explanation:
Given parameters:
Mass of steam = 150g = 0.15kg
Initial temperature of steam = 100°C
Final temperature of water = 100°C
Unknown:
Quantity of heat that must be removed to condense the steam = ?
Solution:
The heat involved here is a latent heat because there is no change temperature. The process is just a phase change.
H = mL
m is the mass
L is the latent heat of vaporization = 2,260 kJ/kg
Insert the parameters and solve;
H = 0.15kg x 2,260 kJ/kg
H = 339kJ
<h3>
<u>moles of H2SO4</u></h3>
Avogadro's number (6.022 × 1023) is defined as the number of atoms, molecules, or "units of anything" that are in a mole of that thing. So to find the number of moles in 3.4 x 1023 molecules of H2SO4, divide by 6.022 × 1023 molecules/mole and you get 0.5646 moles but there are only 2 sig figs in the given so we need to round to 2 sig figs. There are 0.56 moles in 3.4 x 1023 molecules of H2SO4
Note the way this works is to make sure the units are going to give us moles. To check, we do division of the units just like we were dividing two fractions:
(molecules of H2SO4) = (molecules of H2SO4)/1 and so we have 3.4 x 1023/6.022 × 1023 [(molecules of H2SO4)/1]/[(molecules of H2SO4)/(moles of H2SO4)]. Now, invert the denominator and multiply:
<h3 />
Answer:
By balancing the chemical equation
Explanation:
The Law of Conservation of Matter states that matter cannot be destroyed nor created.
That is, you must have the same amount of matter before and after a reaction.
Atoms are made of matter, so you must have the same number of each type of atom in the reactants as in the products. You must balance the equation.
Consider the reaction
2H₂ + O₂ ⟶ 2H₂O
You must have 2s in front of H₂ and H₂O to balance the atoms.
They give you four atoms of H and two atoms of O on each side of the arrow.
