Which phrase describes the movement of the continents?

s) Suppose we now collect hydrogen gas, H2(g), over water at 21◦C in a vessel with total pressure of 743 Torr. If the hydrogen g

Elenna [48]

This is an incomplete question, here is a complete question.

Suppose we now collect hydrogen gas, H₂(g), over water at 21°C in a vessel with total pressure of 743 Torr. If the hydrogen gas is produced by the reaction of aluminum with hydrochloric acid:

$2Al(s)+6HCl(aq)\rightarrow 2AlCl_3(aq)+3H_2(g)$

what volume of hydrogen gas will be collected if 1.35 g Al(s) reacts with excess HCl(aq)? Express your answer in liters.

Answer : The volume of hydrogen gas that will be collected is 1.85 L

Explanation :

First we have to calculate the number of moles of aluminium.

Given mass of aluminium = 1.35 g

Molar mass of aluminium = 27 g/mol

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

$\text{Moles of aluminium}=\frac{1.35g}{27g/mol}=0.05mol$

The given chemical reaction is:

$2Al(s)+6HCl(aq)\rightarrow 2AlCl_3(aq)+3H_2(g)$

As, hydrochloric acid is present in excess. So, it is considered as an excess reagent.

Thus, aluminium is a limiting reagent because it limits the formation of products.

By Stoichiometry of the reaction:

2 moles of aluminium produces 3 moles of hydrogen gas

So, 0.005 moles of aluminium will produce = $\frac{3}{2}\times 0.05=0.0750mol$ of hydrogen gas

Now we have to calculate the mass of helium gas by using ideal gas equation.

PV = nRT

where,

P = Pressure of hydrogen gas = 743 Torr

V = Volume of the helium gas = ?

n = number of moles of hydrogen gas = 0.075 mol

R = Gas constant = $62.364\text{ L Torr }mol^{-1}K^{-1}$

T = Temperature of hydrogen gas = $21^oC=[21+273]K=294K$

Now put all the given values in above equation, we get:

$743Torr\times V=0.075mol\times 62.364\text{ L Torr }mol^{-1}K^{-1}\times 294K\\\\V=1.85L$

Hence, the volume of hydrogen gas that will be collected is 1.85 L

8 0

3 years ago

Significant Figures: How many significant figures<br> are in 865,010?

Harrizon [31]

Answer: There are five significant figures in 865,010.

Explanation:

When a degree of accuracy is stated by each digit present in a mathematical figure then it is called a significant figure.

Rules for counting significant figures is as follows.

Any non-zero digits and zeros present between a non-zero figure are counted. For example, 3580009 has seven significant figures.

Trailing zeros are counted in a non-zero figure. For example, 0.00250 has three significant figures.

Leading zeros are not counted. For example, 0.0025 has two significant figures.

So, in the given figure 865010 has five significant figures and the trailing zero will not be counted.

Thus, we can conclude that there are five significant figures in 865,010.

7 0

3 years ago

Morgan did an experiment to see the effect of water temperature on the rate at which sugar dissolves. She placed a sugar cube in

Dominik [7]

Answer:

B is correct → since temperature can be measured confidently and the variations with temperature are greater ( then the errors in measuring time diminishes)

Explanation:

A is not correct → since the sugar cubes will be still surrounded by water at the temperature chosen regardless of the size of the glass, organising the data by size of the glass is not correct since the glass size does not affect in a significant way to the results ( it could affect the cooling rate of water due to the exposed surface , it but would be insignificant)

C is not correct → since the sugar cubes are approximately of the same size , putting 2 cubes or "n" cubes will not affect the time significantly since each cube is still surrounded by water at the same temperature and behaves independently from others , then each cube dissolves at the same time ( there would be small variations due to the different sizes of the cubes and the small variation due to the limited mass of water)

D is not correct → since the solubility of sugar in water is high , the amount left after the experiment would be very small ( thus the relative errors are high) and the sugar would be contaminated with water in the weighting operation, leading to more errors

B is correct → since temperature can be measured confidently and the variations with temperature are greater ( then the errors in measuring time diminishes)

7 0

3 years ago

Read 2 more answers

Conduction is the transfer of energy by the movement of currents. ture or false <br>

Mandarinka [93]

conduction is the transfer of energy by the movement of currents(it is true)

8 0

3 years ago

Read 2 more answers

the individual components of a solution_____.a: can be separated by physical meansb: are chemically combinedc: react to form com

kap26 [50]

I believe the correct response is A. Can be separated by physical means.

4 0

3 years ago