There a 9 planets in the solar system.
Answer:
It is a physical change.
Explanation:
While it is a chemical reaction because the salt gets dissolved, if you were to boil the water off of a salt solution, all that would be left is salt. This can be done physically. Thus, it is a physical change.
A 1. 00 ml sample of an unknown gas effuses in 11. 1 min. an equal volume of h2 in the same apparatus under the same conditions effuses in 2. 42 minutes then the molar mass of the unknown gas is 41.9.
Molar mass of H2 = 2
Molar mass of unknown gas = ?
rate 1 = 11.1
rate 2 = 2.42
<h3>What is graham law? </h3>
Graham's law states that the rate of diffusion or effusion of a given gas is inversely proportional to the square root of its molar mass.
By apply graham law
Rate1/rate2 = sqrt(MW2/MW1)
![[\frac{rate1}{rate2} ]^{2} = \frac{MW2}{2} \\\\\\mw= 2[\frac{11.1}{2.42} ]^{2} \\\\= 20.97 X 2 \\\\= 41.9](https://tex.z-dn.net/?f=%5B%5Cfrac%7Brate1%7D%7Brate2%7D%20%5D%5E%7B2%7D%20%3D%20%5Cfrac%7BMW2%7D%7B2%7D%20%5C%5C%5C%5C%5C%5Cmw%3D%202%5B%5Cfrac%7B11.1%7D%7B2.42%7D%20%5D%5E%7B2%7D%20%5C%5C%5C%5C%3D%2020.97%20X%202%20%5C%5C%5C%5C%3D%2041.9)
Thus, we found that the molar mass of the unknown gas is 41.9.
Learn more about graham's law: brainly.com/question/12415336
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It’s been awhile but I think it is c
A student measures the volume of a solution to be 0.01370 have 5 significant digits in this measurement.
<h3>What are significant digits?</h3>
The significant digits are the minimum number from zero to nine for reporting any measurement where the digits are uncertain.
The significant digits starting from zero are not significant digits, decimal is not a significant digit, and ending zero after the decimal are significant digits.
Therefore, the student measures the volume of a solution to be 0.01370 5 significant digits are in this measurement.
Learn more about significant digits, here:
brainly.com/question/1658998
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