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3 years ago

Identify and explain exothermic and endothermic reactions in terms of energy transfer

1 answer:

5 0

Exothermic reaction is when the system releases energy to the surrounding, the energy (in the perspective of the system) will have a sign of negative, as the system is transferring energy towards the surrounding.

Endothermic reaction is when the system is absorbing energy from the surrounding, the energy (in the perspective of the system) will have a sign of positive, as energy is transferred to the system.

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1/2 - 3/7=??????????????????????

Veseljchak [2.6K]

1/2 - 3/7 = 7/14 - 6/14 = 1/14

6 0

3 years ago

A pharmaceutical company is making a large volume of nitrous oxide (NO). They predict they will be able to make a maximum amount

iragen [17]

Answer:

The answer is "Option B"

Explanation:

From the query, the following knowledge is derived:

Yield in percentage = 47%

Performance of theory = 4860 g

Actual yield Rate =?

The percentage return is defined simply by the ratio between both the real return as well as the conceptual return multiplied by the 100. It's also represented as numerically:

$Rate = \frac{Existing \ Rate} {Theoretical \ Rate} \times 100$

Now We can obtain the percent yield as followed using the above formula:

$\text{Yield in percentage}= \frac{Actual \ yield \ Rate} {Theorical \ Rate} \times 100$

$47\% = \frac{Actual \ yield \ Rate}{4860}$

The value of the Actual yield Rate = $47\% \times 4860$

$= \frac{47}{100} \times 4860 \\\\ = 2284.2 g$

The Actual yield Rate= 2284.2 g.

3 0

2 years ago

What method would you use to find the volume of an irregularly shaped object?

dimulka [17.4K]

Displacement, usually the method that is used to measure the volume of an irregularly shaped object.

4 0

3 years ago

It is found that a gas undergoes a first-order decomposition reaction. If the rate constant for this reaction is 8.1 x 10-2 /min

kap26 [50]

Answer:

28.43 min

Explanation:

Using integrated rate law for first order kinetics as:

$[A_t]=[A_0]e^{-kt}$

Where,

$[A_t]$ is the concentration at time t

$[A_0]$ is the initial concentration

Given that:

The rate constant, k = $8.1\times 10^{-2}$ min⁻¹

Initial concentration $[A_0]$ = 0.1 M

Final concentration $[A_t]$ = $1.0\times 10^{-2}$ M

Time = ?

Applying in the above equation, we get that:-

$1.0\times 10^{-2}=0.1e^{-8.1\times 10^{-2}\times t}$

$0.1e^{-8.1\times \:10^{-2}t}=10^{-2}$

$e^{-8.1\times \:10^{-2}t}=\frac{1}{10}$

$\ln \left(e^{-8.1\times \:10^{-2}t}\right)=\ln \left(\frac{1}{10}\right)$

$t=28.43\ min$

3 0

3 years ago

Which reactions are single displacement reactions? 2NaBr + CaF2 → 2NaF + CaBr2 SnO2 + 2H2 → Sn + 2H2O 4Na + O2 → 2Na2O 2KClO3 →

r-ruslan [8.4K]

Answer : The correct options are, $SnO_2+2H_2\rightarrow Sn+2H_2O$ and $2Al+6HCl\rightarrow 2AlCl_3+3H_2$

Explanation :

Single displacement reaction : It is a type of chemical reaction in which the more reactive element displaces the less reactive element.

Option A reaction : $2NaBr+CaF_2\rightarrow 2NaF+CaBr_2$

It is an example of double displacement reaction because in this reaction a positive cation and a negative anion of the two reactants exchange their places to form two new products.

Option B reaction : $SnO_2+2H_2\rightarrow Sn+2H_2O$

It is an example of single displacement reaction.

Option C reaction : $4Na+O_2\rightarrow 2Na_2O$

It is an example of combination reaction because in this reaction two reactants react to give a single product.

Option D reaction : $2KClO_3\rightarrow 2KCl+3O_2$

It is an example of decomposition reaction because in this reaction a single reactant decomposes into two or more products.

Option E reaction : $2Al+6HCl\rightarrow 2AlCl_3+3H_2$

It is an example of single displacement reaction because in this reaction the most react element, aluminium displaces the less reactive element, hydrogen.

Hence, the options B and E are single displacement reactions.

5 0

3 years ago