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dedylja [7]

Hydropower is one of the oldest renewable resources and has been used for thousands of years.

5 0

2 years ago

For the following electrochemical cell, determine the oxidizing agent, reducing agent, and whether the cell is a voltaic cell or

lyudmila [28]

1637947 d hdidmbdjrn

4 0

3 years ago

A mixture contains only NaCl and Al2(SO4)3. A 1.45-g sample of the mixture is dissolved in water, and an ex- cess of NaOH is add

chubhunter [2.5K]

Answer:

The mass percent of aluminum sulfate in the sample is 16.18%.

Explanation:

Mass of the sample = 1.45 g

$Al_2SO_3+6NaOH\rightarrow 2Al(OH)_3+3Na_2SO_4$

Mass of the precipitate = 0.107 g

Moles of aluminum hydroxide = $\frac{0.107 g}{78 g/mol}=0.001372 mol$

According to reaction, 2 moles of aluminum hydroxide is obtained from 1 mole of aluminum sulfate .

Then 0.001372 moles of aluminum hydroxide will be obtained from:

$\frac{1}{2}\times 0.001372 mol=0.000686 mol$

Mass of 0.000686 moles of aluminum sulfate :

= 0.000686 mol × 342 g/mol = 0.2346 g

The mass percent of aluminum sulfate in the sample:

$=\frac{ 0.2346 g}{1.45g}\times 100=16.18\%$

5 0

3 years ago

A gas that exerts a pressure of 537 torr in a container with a volume of 5.30 L will exert a pressure of 255 torr when transferr

ArbitrLikvidat [17]

Answer:- The gas needs to be transferred to a container with a volume of 11.2 L.

Solution:- From Boyle's law. "At constant temperature, Volume is inversely proportional to the pressure."

It means, the volume is decreased if the pressure is increased and vice versa.

Here, the Pressure is decreasing from 537 torr to 255 torr. So, the volume must increase and calculated by using the equation:

$P_1V_1=P_2V_2$

Where, $P_1$ is initial pressure and $P_2$ is final pressure. Similarly, $V_1$ is initial volume and $V_2$ is final volume.

Let's plug in the values in the equation:

(537 torr)(5.30 L) = (255 torr)( $V_2$ )

$V_2=(\frac{537 torr*5.30 L}{255 torr})$

$V_2$ = 11.2 L

So, the new volume of the container needs to be 11.2 L.

4 0

3 years ago

Using your knowledge of reagents that react with alkenes, what would be a reagent that you could use to check and see if the hyd

igomit [66]

Answer:

An halogen addition reaction, particularly bromine addition, could be used to check if the hydrogenation has completed.

Explanation:

The aim is to find a way to check if the hydrogenation process of an alkene has completed. So the logic should be use a reaction that needs the participation of the double bound of the alkene, and therefore shouldn't take place in the process has finished.

A simple organic reaction is the halogen addition reaction, which occur between the halogen molecule and the double bond of the alkene. Basically, the pi electrons of the double bond attacks a relatively electrophilic halogen atom following a mechanism that leads to the addition of two halogen atoms to the double bond. As a consequence the alkene transforms into an haloalkane.

Also, a commonly used halogen is bromine, as it has a reasonable reactivity and it has red colour, which allows to monitor the progression of the reaction.

Taking all this in account, we can say that using a bromine addition reaction to the alkene it's a good option to check the completion of the hydrogenation.

Note that the bromine will react only if the double bond is present. So, if the hydrogenation has completed, the reaction won't occur. Using bromine will be the best option, as it is red coloured. That means that is we add bromine to an incomplete hydrogenation, as it will react with the alkene, the colour should disappear.

In other words, to check if the hydrogenation reaction has completed, we should add bromine and see what happens to the colour. If it doesn't change, then the hydrogenation reaction has completed.

3 0

3 years ago