Molecules are likely to dissolve in nonpolar solvents.

2) Gas molecules do not have preferred direction of motion, their motion is completely random. 3) Gas molecules travels in straight line. 4) The time interval of collision between any two gas molecules is very small. 5) The collision between gas molecules and the walls of container is perfectly elastic.

3 0

2 years ago

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Reaction of 0.028 g of magnesium with excess hydrochloric acid generated 31.0 mL of hydrogen gas. The gas was collected by water

MA_775_DIABLO [31]

Explanation:

(a) It is given that magnesium is reacted with hydrochloric acid and the hydrogen evolved is collected at top. This means that hydrochloric acid will be present in a solution (HCl + Water) and the solvent will be water.

Due to evaporation some amount of water will have evaporated and would be present in vapor phase. Therefore, when the reaction occurs only hydrogen will not be present in vapor phase but, will be accompanied by water vapors as well .

Hence, Dalton's law the total pressure of the system will be sum of pressure exerted by hydrogen gas and pressure exerted by water vapors .

Let us assume that the partial pressure of hydrogen gas be " $P_H_{2}$ "

And, the partial pressure of water will be nothing but the vapor pressure of water,

Vapor pressure of water = $P_{water}$

= 19.8 mm Hg

Total pressure of the system = 746 mm Hg

Total pressure = $P_H_{2} + P_{water}$

746 = $P_H_{2}$ + 19.8

or, $P_H_{2}$ = 746-19.8

= 726.2 mm Hg

Hence, partial pressure of hydrogen gas is 726.2 mm Hg.

(b) To calculate volume at STP, we will first calculate at $22^{o}C$ and 726.2 mm Hg and than convert it to STP conditions.

Therefore, to calculate volume at $22^{o}C$ and 726.2 mm Hg we will make use of ideal gas law as follows.

P = 726.2 mm Hg

= $\frac{726.2}{760}$

= 0.955 atm

T = $22^{o}C$

= 22+273.15 = 295.15 K

V = 31 ml = $31 \times 10^{-3}$ Litre

According to the ideal gas law ,

PV = nRT

where, P = pressure of the system ,

V = volume of the gas

N = number of moles

R = 0.0821 liter atm/mole K

T = Temperature

Hence, putting the given values into the above formula as follows.

$0.955 \times 31 \times 10^{-3} = N \times 0.0821 \times 295.15$

N = $1.222 \times 10^{-3}$ moles

Now, the moles of hydrogen won't change. Therefore, let us calculate volume at STP of $1.222 \times 10^{-3}$ moles of hydrogen.

Now, at STP T = 273.15 K , P = 1 atm and N = $1.222 \times 10^{-3}$ moles

$1 \times V = 1.222 \times 10^{-3} \times 0.0821 \times 273.15 K$

V = 0.027398 Litre

= $0.027398 \times 1000$ (as 1 L = 1000 ml)

= 27.398 ml

Therefore, volume of hydrogen at STP is 27.398 ml .

(c) Now, we can write the the reaction for this case as follows.

$Mg + 2HCl \rightarrow MgCl_{2} + H_{2}$

As, weight of magnesium = 0.028 grams

Molar mass of magnesium = 24.3 grams/mole

Number of moles of magnesium = $\frac{mass}{\text{molar mass}}$

= $\frac{0.028}{24.3}$

= $1.15226 \times 10^{-3}$ moles

Since, it can be seen from the reaction that

1 mole of Magnesium = 1 mole of hydrogen

and, moles of hydrogen = $1.15226 \times 10^{-3}$ moles

= 0.001523 moles

Hence, theoretical number of moles of hydrogen that can be produced from 0.028 grams of Mg is 0.001523 moles

8 0

3 years ago

Determine whether the graph is that of a function by using the vertical-line test. If it is, use the graph to find (a) its domai

Ilia_Sergeevich [38]

Answer:

Following are the solution to this question:

Explanation:

If the draw a line perpendicular with y-axis thru the diagonal line check but it meets only one curved point, therefore the curve indicates a function not otherwise. They draw a vertical line perpendicular to the y-axis there, it just intersects one more chart point, which is why a graph is a feature:

In point a:

$\to Domain= [-\pi ,\pi ]\\\\\to Range = [-1,1]$

In point b:

Its y-axis length cut also by understanding the benefits of y-interception and the x-axis length gives the x-intercept.

$\to y-intercept = 1\\\\\to x-intercept = \frac{\pi}{2} ,- \frac{\pi}{2} \\\\$

In point C:

Every graph is y-axis symmetric because the left side of the column as well as the middle side of the graph is about the same.

3 0

2 years ago