NaCl IS READILY SOLUBLE IN WATER DUE TO HIGH HYDRATION ENERGY
BUT HAVE HIGH MELTING POINT DUE TO STRONG ELECTROSTATIC FORCE BETWEEN SODIUM AND CHLORIDE IONS.
Explanation:
Sodium has low melting point 98 deg celcius. In water sodium gets floated.
But sodium chloride have a high melting point because lattice is constructed due to strong electro-static force between positive sodium ions and negative chloride ions as they attract each other. This leads to strong construction so, NaCl have high temperature to break the bonds between the ions.
The melting temperature depends on the charge of the ions. Due to high hydration energy the sodium ions are readily soluble in water. Water can dissolve salt because the positive part of water molecules attracts negative chloride ions and negative part of water molecules attracts positive sodium ions.
Answer:
-2.80 × 10³ kJ/mol
Explanation:
According to the law of conservation of energy, the sum of the heat absorbed by the bomb calorimeter (Qcal) and the heat released by the combustion of the glucose (Qcomb) is zero.
Qcal + Qcomb = 0
Qcomb = - Qcal [1]
We can calculate the heat absorbed by the bomb calorimeter using the following expression.
Qcal = C × ΔT = 4.30 kJ/°C × (29.51°C - 22.71°C) = 29.2 kJ
where,
C: heat capacity of the calorimeter
ΔT: change in the temperature
From [1],
Qcomb = - Qcal = -29.2 kJ
The internal energy change (ΔU), for the combustion of 1.877 g of glucose (MW 180.16 g/mol) is:
ΔU = -29.2 kJ/1.877 g × 180.16 g/mol = -2.80 × 10³ kJ/mol
Answer:
3.23945533x
g
Explanation:
mass of 1 atom Pt = mass of a mole of atom Pt / 6.022 x 
= 195.08/6.022 x = 3.23945533xg
I think it's D but not sure
