Electrons and protons
Answer:A
The balanced chemical reaction is:
CH4 + 2O2 —> CO2 + 2H2O
You need to convert mass to moles (divide by molar mass):
CH4 moles = 5 / 16 = 0.31 mol
O2 moles = 5 / 32 = 0.16 mol
To figure out which reactant is limiting, divide the actual moles by the corresponding coefficient in the reaction:
CH4: 0.31 / 1 = 0.31
O2: 0.16 / 2 = 0.08
O2 is the lower number, so it is the limiting reactant. From the reaction we know it takes 2 moles of O2 to react with each mole of CH4. Therefore, for however many moles of O2 we actually have, half as many moles of CH4 will react. Since we have 0.16 mol of O2, only 0.08 mol of CH4 will react, leaving behind 0.31 - 0.08 = 0.23 mol of CH4.
Now convert back to mass (multiply by molar mass) to find the mass of CH4 remaining:
0.23 x 16 = 3.68g
The closest answer is B.
Answer: 
moles
Explanation:
We are given:
Moles of electron = 1 mole
According to mole concept:
1 mole of an atom contains 
number of particles.
We know that:
Charge on 1 electron = 
Charge on 1 mole of electrons = 
The metal being plated has a +4 charge, thus the equation will be:
of electricity deposits = 1 mole of metal
Thus 861.8 C of electricity deposits =
moles of metal
Thus moles of metal should be plated
<u>Answer:</u> The concentration of KOH solution is 1.215 M
<u>Explanation:</u>
For the given chemical equation:
To calculate the concentration of base, we use the equation given by neutralization reaction:
where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is KOH.
We are given:
Putting values in above equation, we get:
Hence, the concentration of KOH solution is 1.215 M
Yes, an explanation/ theory for a phenomena in science is not something that is set in stone. If experiments are done that prove the current explanation is false and this is peer checked, then the explanation can absolutely be proven false.
