This is an incomplete question, here is a complete question.
The conversion of cyclopropane to propene occurs with a first-order rate constant of 2.42 × 10⁻² hr⁻¹. How long will it take for the concentration of cyclopropane to decrease from an initial concentration 0.080 mol/L to 0.053 mol/L?
Answer : The time taken will be, 17.0 hr
Explanation :
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial concentration of the reactant = 0.080 M
a - x = concentration left = 0.053 M
Now put all the given values in above equation, we get


Therefore, the time taken will be, 17.0 hr
I am assuming you are talking about Neon. The rate of diffusion is directly proportional to the molar mass of the gas. Since neon has a molar mass of 20.18 grams, the gas must have a lower molar mass and must be a gas at 273 Kelvin. There are several elements that fulfill this criteria: Hydrogen, Helium, Oxygen, Nitrogen, and Fluorine.
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<span>if we assume volume NaCl + volume H2O = volume H2O.. i.e.. NaCl does not effect volume </span>
<span>therefore.. the units of.. </span>
<span>.. M = moles NaCl / L solution ≈ moles NaCl / L H2O </span>
<span>.. density = grams NaCl / L solution ≈ grams NaCl / L H2O </span>
<span>again.. that is our assumption </span>
<span>so we can readily see that </span>
<span>.. M = (1 mol NaCl / ___g NaCl) x (__g NaCl / L H2O) + 0 </span>
<span>ie.. </span>
<span>.. M = (1 mol NaCl / 58.5g NaCl) x density solution + 0 </span>
<span>so.. we would expect.. </span>
<span>.. m = 0.01709 mol / g </span>
<span>.. b = 0 </span>
Answer: Gases are complicated. They're full of billions and billions of energetic gas molecules that can collide and possibly interact with each other. Since it's hard to exactly describe a real gas, people created the concept of an Ideal gas as an approximation that helps us model and predict the behavior of real gases. The term ideal gas refers to a hypothetical gas composed of molecules which follow a few rules:
Ideal gas molecules do not attract or repel each other. The only interaction between ideal gas molecules would be an elastic collision upon impact with each other or an elastic collision with the walls of the container. [What is an elastic collision?]
Ideal gas molecules themselves take up no volume. The gas takes up volume since the molecules expand into a large region of space, but the Ideal gas molecules are approximated as point particles that have no volume in and of themselves.
If this sounds too ideal to be true, you're right. There are no gases that are exactly ideal, but there are plenty of gases that are close enough that the concept of an ideal gas is an extremely useful approximation for many situations. In fact, for temperatures near room temperature and pressures near atmospheric pressure, many of the gases we care about are very nearly ideal.
If the pressure of the gas is too large (e.g. hundreds of times larger than atmospheric pressure), or the temperature is too low (e.g.
−
200
C
−200 Cminus, 200, start text, space, C, end text) there can be significant deviations from the ideal gas law.
Explanation: