Answer:
60.7 mole
Explanation:
for every 4 moles of iron 3 moles of oxygen is used.
So, moles of oxygen = 
= 60.675
Aluminium-27 is an isotope of aluminium characterized by the fact that is has a mass number equal to 27.
Now, an atom's mass number tells you the total number of protons and of neutrons that atom has in its nucleus. Since you're dealing with an isotope of aluminium, it follows that this atom must have the exact same number of protons in its nucleus.
The number of protons an atom has in its nucleus is given by the atomic number. A quick looks in the periodic table will show that aluminium has an atomic number equal to 13.
This means that any atom that is an isotope of aluminium will have 13 protons in its nucleus.
Since you're dealing with a neutral atom, the number of electrons that surround the nucleus must be equal to the number of protons found in the nucleus.
Therefore, the aluminium-27 isotope will have 13electrons surrounding its nucleus.
Finally, use the known mass number to determine how many neutrons you have
mass number=no. of protons+no. of neutrons
no. of neutrons=27−13=14
hope this helps.
The answer:
according to Boyle's law concerning Pressure (P), Volume (V), Temperature (T) and number of mole (n) , we have the famous formula:
PiVi = Pf Vf,
Pi=1.9kPa
Vi= 4L
Vf = 12L
T=25
n=3
Pf = ?
let's find the value of Pf
from the equation
PiVi = Pf Vf we can have Pf= PiVi / Vf
Pf = 1.9*4 / 12 = 0.63
so the answer is <span>B. 0.63 kPa</span>
Density is mass by volume
1 mL of nitric acid solution has a mass of 1.36 g
therefore 1000 mL has a mass of 1360 g
the molarity of solution is 2.48 mol/L
1 L of solution has 2.48 mol
the mass of 2.48 mol of HNO₃ is - 2.48 mol x 63 g/mol = 156.24 g
this means that 156.24 g of the solution consists of nitric acid
therefore percentage by mass - mass of nitric acid / total mass x 100%
concentration as percentage by mass = 156.24 g / 1360 g x 100%
percentage = 11.5%
Answer:
A catalyst increases the rate of reaction by decreasing activation energy. ... Enzymes are highly substrate specific and catalyze reactions by providing an alternate pathway of lower activation energy.
Explanation:
I hope this helps :)
