A strong electrolyte like MgCl2 dissociates completely as per the following reaction:
As you can see, from 1 molecule of MgCl2 produces 3 ions on dissociation.
So, 1 mole of MgCl2 produces 3 moles of ions.
Now, Moles of MgCl2 = Volume x Molarity
= 0.04 x 0.345 [Change volume to Litres]
= 0.0138 moles
Now, total moles of ions = 0.0138 x 3 = 0.0414
Answer:
D) burning a candle
A demonstration that contains both physical and chemical changes will be BURNING OF A CANDLE.
<em>This is because when a candle is lighted up, on the top of it (where we see flame) the oxygen and other gases present around will be chemically changed (burned up)</em>
<em>When the wax in the top of the candle will get melted due to the heat of the fire a physical change takes places.</em>
<u>Answer:</u> The concentration of radon after the given time is
<u>Explanation:</u>
All the radioactive reactions follows first order kinetics.
The equation used to calculate half life for first order kinetics:
We are given:
Putting values in above equation, we get:
Rate law expression for first order kinetics is given by the equation:
where,
k = rate constant =
t = time taken for decay process = 3.00 days
= initial amount of the reactant =
[A] = amount left after decay process = ?
Putting values in above equation, we get:
Hence, the concentration of radon after the given time is
Answer:
This is because it is a physical change not a chemical change.
hydrogen is not balanced
the right balanced equation is
Fe2O3 + 3 H2 -> 2Fe + 3H2O