Answer:
Cr(s) ⟶ Cr⁴⁺(aq) + 4e⁻
Explanation:
1. Write the skeleton half-reaction
Cr(s) ⟶ Cr⁴⁺(aq)
2. Balance charge
Add electrons to the side that needs them.
You have 4+ on the right and 0 on the left. You must add 4e⁻ to the right to balance the charge.
Cr(s) ⟶ Cr⁴⁺(aq) + 4e⁻
3 Common States of Matter:
1. Solid - particles are motionless and stick together very closely.
2. Liquid - particles are moving slowly without pattern.
3. Gas - Particles are moving rapidly again without pattern.
Answer:
Filtration
Explanation:
Metal carbonate is insoluble, it is possible to filter off the unreacted substances leaving the desired salt solution
Answer:
the heat rate required to cool down the gas from 535°C until 215°C is -2.5 kW.
Explanation:
assuming ideal gas behaviour:
PV=nRT
therefore
P= 109 Kpa= 1.07575 atm
V= 67 m3/hr = 18.6111 L/s
T= 215 °C = 488 K
R = 0.082 atm L /mol K
n = PV/RT = 109 Kpa = 1.07575 atm * 18.611 L/s /(0.082 atm L/mol K * 488 K)
n= 0.5 mol/s
since the changes in kinetic and potencial energy are negligible, the heat required is equal to the enthalpy change of the gas:
Q= n* Δh = 0.5 mol/s * (- 5 kJ/mol) =2.5 kW
Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :
where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get
Therefore, the molecular weight of a substance is 157.3 g/mol
