Answer: The ratio of carbon dioxide molecules to oxygen molecules is 20 :31
Explanation:
Combustion is a chemical reaction in which hydrocarbons are burnt in the presence of oxygen to give carbon dioxide and water.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced combustion reaction is,:
Thus the ratio of carbon dioxide molecules to oxygen molecules is 20 : 31
Answer: CoBr3 < K2SO4 < NH4 Cl
Justification:
1) The depression of the freezing point of a solution is a colligative property, which means that it depends on the number of particles of solute dissolved.
2) The formula for the depression of freezing point is:
ΔTf = i * Kf * m
Where i is the van't Hoof factor which accounts for the dissociation of the solute.
Kf is the freezing molal constant and only depends on the solvent
m is the molality (molal concentration).
3) Since, you are assuming equal concentrations and complete dissociation of the given solutes, the solute with more ions in the molecular formula will result in the solution with higher depression of the freezing point (lower freezing point).
4) These are the dissociations of the given solutes:
a) NH4 Cl (s) --> NH4(+)(aq) + Cl(-) (aq) => 1 mol --> 2 moles
b) Co Br3 (s) --> Co(3+) (aq) + 3Br(-)(aq) => 1 mol --> 4 moles
c) K2SO4 (s) --> 2K(+) (aq) + SO4 (2-) (aq) => 1 mol --> 3 moles
5) So, the rank of solutions by their freezing points is:
CoBr3 < K2SO4 < NH4 Cl
Positive ions or molecules that have lost one or more electrons where negative ions are actually oxygen atoms with extra negatively charged electrons.
Answer:
i believe that the answer is c
Explanation:
I think its c because because its used as a bed rock layer
Answer:
12
Explanation:
To get to this answer you have to look at the number first. So the given number is 12.47 and you need 2 sig figs.
To help you understand this more start off by underlining the first 2 numbers because 2 sig figs are needed. <u>12</u>.47
Now you want to look at the number after the underlined (I bolded that number). <u>12</u>.47
If the number is above 5 then you would round the previous number up by one but in this case it is 4 so you do not increase the number. Hence, you getting 12 as your final answer.
Hope this helped! Let me know if you have any questions.
