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4 years ago

Any tips for Chemistry Practical? Im taking my Olevel practical tmr. Anyone?

Chemistry

1 answer:

garik1379 [7]4 years ago

3 0

Answer:

re-do test if needed

Explanation:

if you're done early for the practical, check your answers back to the solutions. If feel the need to re-check if the answers are somewhat correct, re-do the steps :) all the best!

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Can someone help? Ill give brainliest!

-Dominant- [34]

Answer:

Explanation:

before the reaction you have N=2 and H=6 after the reaction you have N=2 and H=6 so yes it follows the law

7 0

3 years ago

An unknown substance dissolves in water but it does not conduct electricity before or after it has dissolved. What type of bondi

GarryVolchara [31]

Since it dissolves in water but doesn't conduct electricity means its not forming ions like salt. since it dissolves though it means it has to have some charge on the molecule to bond with water molecules. suger would be an example.

7 0

3 years ago

Lion 7

Sidana [21]

Answer:

Explanation:

You should NEVER eat or drink anything in a lab area. You never know what chemicals or gases are in the lab, and they can harm you.

Wearing a drawstring hoodie won't protect you from chemicals.

Don't wait to clean up chemicals, immediately get a teacher and clean it up (follow the teachers instructions). You never know what has spilled, and if it is harmful or not, or if there is a certain procedure to clean it up.

Don't change the equipment in the middle of an experiment. This can tamper with your results, and depending on what you are working with, this can be dangerous.

3 0

3 years ago

In the first step of the Ostwald process for the synthesis of nitric acid, ammonia is converted to nitric oxide by the high-temp

Paul [167]

Solution: The given balanced equation is:

$4NH_3+5O_2\rightarrow 4NO+6H_2O$

If we have a hypothetical equation:

$A+2B\rightarrow 3C+5D$

Then the rate could be written as:

$rate=-\frac{\Delta [A]}{\Delta t}=-\frac{1}{2}\frac{\Delta [B]}{\Delta t}=\frac{1}{3}\frac{\Delta [C]}{\Delta t}=\frac{1}{5}\frac{\Delta [D]}{\Delta t}$

From above expression one thing could easily be noticed that the coefficients of all are inverted. Also, there is negative sign in front of reactants and positive sign in front of the products. Negative sign stands for rate of consumption where as positive sign stands for rate of formation.

Like the above example, we can write the rate for the given equation and it would be looking as:

$rate=-\frac{1}{4}\frac{\Delta [NH_3]}{\Delta t}=-\frac{1}{5}\frac{\Delta [O_2]}{\Delta t}=\frac{1}{4}\frac{\Delta [NO]}{\Delta t}=\frac{1}{6}\frac{\Delta [H_2O]}{\Delta t}$

Now we can easily answer all the parts of the question.

(a) From above expression, the rate of consumption of $O_2$ related to rate of consumption of $NH_3$ as:

$-\frac{1}{5}\frac{\Delta [O_2]}{\Delta t}=-\frac{1}{4}\frac{\Delta [NH_3]}{\Delta t}$

multiply both sides by -5

$\frac{\Delta [O_2]}{\Delta t}=\frac{5}{4}\frac{\Delta [NH_3]}{\Delta t}$

So, rate of consumption of oxygen is $\frac{5}{4}$ the rate of consumption of ammonia.

(b) The relationship between rate of formation of NO to the rate of consumption of ammonia will be written as:

$\frac{1}{4}\frac{\Delta [NO]}{\Delta t}=-\frac{1}{4}\frac{\Delta [NH_3]}{\Delta t}$

Multiply both sides by 4

$\frac{\Delta [NO]}{\Delta t}=-\frac{\Delta [NH_3]}{\Delta t}$

So, rate of formation of NO equals to the rate of consumption of ammonia.

Now, the rate of formation of $H_2O$ to the rate of consumption of ammonia would be:

$\frac{1}{6}\frac{\Delta [H_2O]}{\Delta t}=-\frac{1}{4}\frac{\Delta [NH_3]}{\Delta t}$

Multiply both sides by 6

$\frac{\Delta [H_2O]}{\Delta t}=-\frac{6}{4}\frac{\Delta [NH_3]}{\Delta t}$

So, the rate of formation of $H_2O$ is $\frac{6}{4}$ times that is 1.5 times to the rate of consumption of ammonia.

5 0

4 years ago

For a galvanic cell that uses the following two half-reactions, Cr2O72-(aq) + 14 H+(aq) + 6 e- → 2 Cr3+(aq) + 7 H2O(l) Pb(s) → P

polet [3.4K]

Answer:

Explanation:

The detailed solution is found in the image attached. It is necessary to note that the oxidation half equation is multiplied by three to balance electron gain and loss. This is adequately shown in the image below. Inferences are only drawn from balanced redox reaction equation hence the first step is to balance the redox reaction equation.

5 0

4 years ago

Any tips for Chemistry Practical? Im taking my Olevel practical tmr. Anyone?​

Any tips for Chemistry Practical? Im taking my Olevel practical tmr. Anyone?