Answer:
Na₂CO₃.2H₂O
Explanation:
For the hydrated compound, let us denote is by Na₂CO₃.xH₂O
The unknown is the value of x which is the amount of water of crystallisation.
Given values:
Starting mass of hydrate i.e Na₂CO₃.xH₂O = 4.31g
Mass after heating (Na₂CO₃) = 3.22g
Mass of the water of crystallisation = (4.31-3.22)g = 1.09g
To determine the integer x, we find the number of moles of the anhydrous Na₂CO₃ and that of the water of crystallisation:
Number of moles = 
Molar mass of Na₂CO₃ =[(23x2) + 12 + (16x3)] = 106gmol⁻¹
Molar mass of H₂O = [(1x2) + (16)] = 18gmol⁻¹
Number of moles of Na₂CO₃ =
= 0.03mole
Number of moles of H₂O =
= 0.06mole
From the obtained number of moles:
Na₂CO₃ H₂O
0.03 0.06
Simplest
Ratio 0.03/0.03 0.03/0.06
1 2
Therefore, x = 2
Answer:
Ca has the greater Ionization Energy because the Trend is I/e decreases as you move down a group. Therefore, Ca has the greater I/e
Explanation:
Answer:
Na.
Explanation:
- The oxidation-reduction reaction contains a reductant and an oxidant (oxidizing agent).
- An oxidizing agent, or oxidant, gains electrons and is reduced in a chemical reaction. Also known as the electron acceptor, the oxidizing agent is normally in one of its higher possible oxidation states because it will gain electrons and be reduced.
- A reducing agent (also called a reductant or reducer) is an element (such as calcium) or compound that loses (or "donates") an electron to another chemical species in a redox chemical reaction.
<em>2Na + S → Na₂S.</em>
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Na is oxidized to Na⁺ in (Na₂S) (loses 1 electron). "reducing agent".
S is reduced to S²⁻ in (Na₂S) (gains 2 electrons). "oxidizing agent".
Answer:
Approximately
.
Explanation:
Balanced equation for this reaction:
.
Look up the relative atomic mass of elements in the limiting reactant,
, as well as those in the product of interest,
:
Calculate the formula mass for both the limiting reactant and the product of interest:
.
.
Calculate the quantity of the limiting reactant (
) available to this reaction:
.
Refer to the balanced equation for this reaction. The coefficients of the limiting reactant (
) and the product (
) are both
. Thus:
.
In other words, for every
of
formula units that are consumed,
of
formula units would (in theory) be produced. Thus, calculate the theoretical yield of
in this experiment:
.
Calculate the theoretical yield of this experiment in terms of the mass of
expected to be produced:
.
Given that the actual yield in this question (in terms of the mass of
) is
, calculate the percentage yield of this experiment:
.