Specific heat of Aluminium is 0.89 g/J
Explanation:
Step 1 :
Specific heat of a substance is the energy absorbed by a substance of unit mass when its temperature increases by one degree.
Energy Absorbed = Specific Heat * Mass of the substance * Temperature Difference
Step 2 :
It is given that 120 g sample absorbs 9612 J energy when the temperature increases from 298K to 388K.
Temperature Difference = 388 K - 298 K = 90 K
Step 3:
Specific Heat = (Energy Absorbed) ÷ (Mass of the substance * Temperature Difference)
Specific Heat = 9612 ÷ (120 * 90) = 0.89 grams / Joule
Step 4:
Answer:
Specific heat of Aluminium is 0.89 g/J
The internal energy has the symbol U. Q is positive if heat is added to the system, and negative if heat is removed;
....."W is positive if work is done by the system"........
and negative if work is done on the system.
So, work done by a system is positive.
Answer:-
KOH determines how much Mg(OH)2 is made.
2 mol of Mg(OH)2 formed
Explanation:-
The balanced equation is
MgCl2 + 2KOH --> Mg(OH)2+ 2KCI,
From seeing the coefficients we notice
2 mol of KOH reacts with 1 mol of MgCl2
4 mol of KOH reacts with 1 x 4 / 2 = 2 mol of MgCl2
3 moles of MgCl2 was added but only 2 mol react.
So we see there is excess MgCl2 .
Hence KOH is the limiting reactant.
So KOH determines how much Mg(OH)2 is made.
We see from the balanced chemical equation,
2 mol of KOH gives 1 mol of Mg(OH)2.
4 mol of KOH will give 1 x 4 /2 = 2 mol of Mg(OH)2.
3Ca(NO₃)₂(aq) + 2Na₃PO₄(aq) → Ca₃(PO₄)₂(s) + 6NaNO₃(aq)
3Ca²⁺ + 6NO₃⁻ + 6Na⁺ + 2PO₄³⁻ → Ca₃(PO₄)₂ + 6Na⁺ + 6NO₃⁻
3Ca²⁺ + 2PO₄³⁻ → Ca₃(PO₄)₂ (calcium phosphate is the precipitate)
