When you add salt to water, you lower to freezing point of the substance.
So for example, normal water freezes at 0°C. But water with salt in it won't freeze at 0°C, because its freezing point is lowered.
In answer to the question. It takes longer for water with salt in it to freeze because the substance requires a lower temperature than normal water to freeze.
The time taken for the same volume of methane gas to diffuse is 7.1 s.
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Rate of gas diffusion</h3>
The rate at which a given mass of diffuses is inversely proportional to the molar mass of the gas.

where;
- M1 is the molar mass of methane (CH4) = 16 g
- M2 is the molar mass of hydrogen as = 2
- t1 is time taken for methane = 20 s
- t2 is the time taken for hydrogen = ?

Thus, the time taken for the same volume of methane gas to diffuse is 7.1 s.
Learn more about rate of gas diffusion here: brainly.com/question/26696466
Answer:
191 °C
Explanation:
We'll begin by calculating the number of mole in 88.0 g of Ne. This can be obtained as follow;
Mass of Ne = 88.0 g
Molar mass of Ne = 20 g/mol
Mole of Ne =?
Mole = mass /molar mass
Mole of Ne = 88 / 20
Mole of Ne = 4.4 moles
Next, we shall determine the temperature. This can be obtained as follow:
Mole of Ne = 4.4 moles
Pressure (P) = 350 KPa
Volume (V) = 48.5 L
Gas constant (R) = 8.314 KPa.L/Kmol
Temperature (T) =?
PV = nRT
350 × 48.5 = 4.4 × 8.314 × T
16975 = 36.5816 × T
Divide both side by 36.5816
T = 16975 / 36.5816
T = 464 K
Finally, we shall convert 464 K to celsius temperature. This can be obtained as follow:
T(°C) = T(K) – 273
T(K) = 464 K
T(°C) = 464 – 273
T(°C) = 191 °C
Thus, the temperature is 191 °C