Answer:
1) Fe = 69.9%
O = 31.1%
2) H = 5.19%
O = 16.5%
N = 28.9%
C = 49.5%
Explanation:
One easy way to do percent compositions is to assume you have 100g of a substance.
1) Lets say we have 100g of Fe2O3.
The total molar mass would be:
The molar mass of the Fe2 alone is:
Thus, the grams of Fe2(out of a 100) could be calculated by multiplying 100g * the molar mass ratio of Fe2 to the whole:
Which is approximately 69.9%.
We can find the amount of O3 by simply subtracting, as the rest of the compound is made of O3. Thus, the % composition of O3 is 31.1%
You can then do this same process to the next question, getting us the following:
H = 5.19%
O = 16.5%
N = 28.9%
C = 49.5%
Answer: D. Sends small electrical impulses to the heart, causing it to beat more
Explanation: A pacemaker is implanted in the chest and helps to treat abnormal heart rhythms especially those causing your heart to skip beats or beat too slow.
Find the moles of BaSO4 first. Then since we know it's a one to one ratio from barium chloride to barium sulfate we can just solve for liters.
<span>First you need to find the moles BaSO4 , and the you will require to find barium sulfate in liters.
</span>12.00gBaSO4 / 233.31 grams per mole
=.05141moles
Molarity=moles/liters
Hence,
Liters=.05141moles/.6Molarity
=.85 liters
Answer:
False
Explanation:
While chemical reactions can proceed in the forward direction , they can in fact also proceed in the backward direction too. The direction they would proceed depends majorly on the state of chemical equilibrium at that particular time for that particular chemical reaction.
It should be known that when a chemical reaction proceeds in the forward way, more products are formed and the reactants are used up. If however, the chemical reaction proceed in the backward way, more reactants are formed and the products are used up.
A practical example is in the case of an exothermic reaction. This is one in which heat is released to the surroundings as a result of the reactants being at a higer energy level compared to the product. Now, depending on the prevailing equilibrium constraint, the reaction could proceed forward or backward.
If for example, the temperature is decreased, this is a constraint being applied to the equilibrium state. The chemical reaction would take a shift and will favor the forward reaction and more of the products will be formed. And also of the temperature is increased, it is the backward reaction that is favored
Physical change is the change we can see with our eyes. Chemical change is the change that we cannot see. Examples: physical change: The Polar ice caps are melting, and we can see that as it happens. Chemical change: The cooking of an egg or some combustion, like a fire. We can't see the chemicals coming from the fire, but there are chemicals coming from what is being burned and is being released into the air that we cannot see.
