Total mass of CaCO3 = 40 amu of Ca + 12amu of C + 16×3 amu of oxygen = 100amu of CaCO3
i.e 100 tonnes of CaCO3 .
mass of CO2 = 12amu of C + 2× 16amu of O = 44 amu of CO2
mass % of CO2 in CaCO3 = (44/100)×100 =44%
i.e
44% of 100 tonnes is CO2.
=44 tonnes of CO2.
therefore, 44% of CO2 is present in CaCO3.
SThe missing coefficient for the skeleton equation below is as follows
skeleton equation
Cr(s) + Fe(No3)2(aq) ------> Fe (s) + Cr(NO3)3 (aq)
the missing coefficient are is as follows
2 Cr(s) + 3 Fe(NO3)2 ---> 3 Fe (s) + 2 Cr(NO3)3
This is obtained by making sure all the molecules are balanced in both sides
Answer:
The value of the heat capacity of the Calorimeter
= 54.4 
Explanation:
Given data
Heat added Q = 4.168 KJ = 4168 J
Mass of water
= 75.40 gm
Temperature change = ΔT = 35.82 - 24.58 = 11.24 ° c
From the given condition
Q =
ΔT +
ΔT
Put all the values in above equation we get
4168 = 75.70 × 4.18 × 11.24 +
× 11.24
611.37 =
× 11.24
= 54.4 
This is the value of the heat capacity of the Calorimeter.
Answer:

Explanation:
Charge on 1 electron =
The expression for charge is:-

Given that:- Charge =


Total number of electrons, n = 
Answer:
0.185moles of Al₂O₃
Explanation:
Mass of Al = 10g
Mass of O₂ = 19g
Equation of the reaction: 4Al + 3O₂ → 2Al₂O₃
This is the balanced reaction equation.
Solution
From the given parameters, the reactant that would determine the extent of the reaction is Aluminium. It is called the limiting reagent. Oxygen is in excess and it is in an unlimited supply.
Working from the known mass to the unknown, we simply solve for the number of moles of Al using the mass given.
Then from the equation, we can relate the number of moles of Al to that of Al₂O₃ produced:
Number of moles of Al = 
= 
= 0.37mol
From the equation:
4 moles of Al produced 2 moles of Al₂O₃
0.37 mole will yield:
= 0.185moles of Al₂O₃