To get the melting point of a solution so, we will use this formula:
ΔT = - mKf
when:
m is molality of the solution
Kf is cryoscopic constant of water = 1.86 C/m
and ΔT is the change in melting point (T2 - 0 °C)
so, now we need to calculate the molality to substitute:
when the molality = moles NaCl / Kg of water
and when moles NaCl = mass / molar mass
= 2.5 g / 58 g/mol
= 0.043 mol
∴ Kg water = volume *density /1000
= 230 mL * 1 g/mL / 1000
= 0.23 Kg
∴ molality = 0.043 / 0.23 =0.187 M
by substitution:
T2-0°C = - 0.187 * 1.86
∴T2 = - 0.348 °C
Answer:
Sodium is higher than Potassium in thesame group
Explanation:
Sodium and potassium are the elements present in the first group of the periodic table. In group, atomic size increases from top to bottom this implies that even atomic radius increases. This causes less attraction force by nucleus on the electrons of outermost orbit of the atom and hence reduces the first ionisation energy, which is the energy required to remove the electron from the outermost orbit of an atom. So, as potassium is below sodium in the group, sodium has greater ionisation energy than potassium
The melting point of the solid form of water, which is ice, is 0°C. When we convert both temperatures to kelvin by adding 273 to each we get the melting point of copper as 1357K and that of ice is 273K. Then, dividing the melting point of copper by the melting point of ice, both in absolute temperature scale. The answer would be 4.97. Thus, the energy of molecules of copper is approximately 5 times compared to that of water.
No, unless the slime or paper is wet.
