3Si + 2N2 --> Si3N4 (as given)
n(Si) = m/MM = 38.25/28.085 = 1.3619 mol
n(N2) = 14.33/2*14.007 = 0.5115 mol
Therefore, N2 is limiting and Si is in excess
The molar ratio of 2N2:Si3N4 is 2:1
So, 0.0575 mol of silicon nitride is formed (dividing 0.5115 by 2)
m of silicon nitride= n*mm = 0.0575*140.283 = 8.06627... g
= 8.066g (4 significant figures)
(hopefully it is right, but double check in case i did something wrong) :)
Answer:
30 kJ
Explanation:
Arrhenius equation is given by:

Here, k is rate constant, A is Pre-exponential factor, Ea is activation energy and T is temperature.
taking natural log of both side
ln k = ln A - Ea/RT
In Arrhenius equation, A, R and T are constant.
Therefore,

is the lowering in activation energy by enzyme,
R = 8.314 J/mol.K
T = 37°C + 273.15 = 310 K


Answer: Ca(OH)2 (aq) + H2SO4 (aq) ----------> CaSO4(aq) + 2H2O(l)
Explanation:
Since this is a neutralization reaction, the end product would be salt and water. In this equation Calcium will displace hydrogen from the acid because it is more reactive, resulting in the formation of CaSO4 (salt), while the displaced H2 molecule combines with OH molecules to form water.
The equation of the reaction is thus;
Ca(OH)2 (aq) + H2SO4 (aq) ----------> CaSO4(aq) + H2O(l), in other to balance it, we add ''2'' to the water molecule in the right hand side of the equation.
Balance equation is
Ca(OH)2 (aq) + H2SO4 (aq) ----------> CaSO4(aq) + 2H2O(l)
The SI unit for distance is metres - m.
The SI unit for speed or velocity is metres per second - m/s.
The SI unit for acceleration is metres per second squared. - m/s^2.
One way you can work out the rate of reaction is by the amount of product that is produced to time. This can also be done with heat and time.
Hope this helps! :)