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3 years ago

On the surface cost benefit analysis seems straightforward

1 answer:

3 0

The steps taken to evaluate each benefit and cost can become quite complicated. In this case, a benefit is defined as anything that increases human well-being, and a cost is anything that decreases it. These definitions and their <span>respective calculations tend to provoke controversy due to the use of valuation.</span>

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You mix 200. mL of 0.400M HCl with 200. mL of 0.400M NaOH in a coffee cup calorimeter. The temperature of the solution goes from

GuDViN [60]

Answer : The enthalpy of neutralization is, 56.012 kJ/mole

Explanation :

First we have to calculate the moles of HCl and NaOH.

$\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=0.400mole/L\times 0.200L=0.08mol$

$\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=0.400mole/L\times 0.200L=0.08mol$

The balanced chemical reaction will be,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.08 mole of HCl neutralizes by 0.08 mole of NaOH

Thus, the number of neutralized moles = 0.08 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = $200mL+200L=400mL$

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 400mL=400g$

Now we have to calculate the heat absorbed during the reaction.

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat absorbed = ?

$c$ = specific heat of water = $4.18J/g^oC$

m = mass of water = 400 g

$T_{final}$ = final temperature of water = $27.78^oC=273+25.10=300.78K$

$T_{initial}$ = initial temperature of metal = $25.10^oC=273+27.78=298.1K$

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

$q=400g\times 4.18J/g^oC\times (300.78-298.1)K$

$q=4480.96J$

Thus, the heat released during the neutralization = -4480.96 J

Now we have to calculate the enthalpy of neutralization.

$\Delta H=\frac{q}{n}$

where,

$\Delta H$ = enthalpy of neutralization = ?

q = heat released = -4480.96 J

n = number of moles used in neutralization = 0.08 mole

$\Delta H=\frac{-4480.96J}{0.08mole}=-56012J/mole=-56.012kJ/mol$

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 56.012 kJ/mole

8 0

3 years ago

Which answer below correctly identifies the type of change and the explination for the boiling of water

katrin [286]

Answer:

Physical change because even though gas formation was observed, the water was undergoing a state change, which means that its original properties are preserved.

Explanation:

Water boiling results in the physical state changing from solid to gaseous water. This moment can be called boiling or vaporizing, which is the change from liquid to gaseous state by heating water. Thus, the "Boiling Point" (PE) of a substance is the temperature at which that substance changes from liquid to gaseous state and, in the case of water, is 100 ° C. When the water reaches this temperature its physical change occurs because, despite the formation of gas, the water was undergoing a state change, which means that its original properties are preserved.

7 0

3 years ago

How many grams of nickel (ni, 58.69 g/mol) are in 1.57 moles of nickel?

myrzilka [38]

The answer is 58.6934. We assume you are converting between grams Nickel and mole. You can view more details on each measurement unit: molecular weight of Nickel or moles The molecular formula for Nickel is Ni. The SI base unit for amount of substance is the mole. 1 grams Nickel is equal to 0.017037690779543 mole.

3 0

4 years ago

Read 2 more answers

Which of the following is a neutralization reaction?A. Na2O(s) + H2O(a) rightarrow 2NaOH(s).B. 4Na(s) + O2(g) rightqrrow 2Na2O(s

Alisiya [41]

Answer:

C. NaOH(s) + HCl(aaq) rightarrow NaCl(s) + H2O(aq)

Explanation:

A neutralization reaction may be defined as the reaction where an acid when it reacts with some base, the products formed are a salt and water.

Simply, we can write,

acid + base ---> salt + water

Here in option (C),

NaOH is sodium hydroxide is an base

HCl is hydrochloric acid

NaCl is sodium chloride and is the common salt

H20 is water

So, option C). NaOH(s) + HCl(aaq) -----> NaCl(s) + H2O(aq) is a neutralization reaction.

7 0

4 years ago

Which statement gives a reason why scientist think that the universe began with an explosion

yaroslaw [1]

I believe the answer is

At the moment it is the best way of explaining our scientific knowledge.

8 0

3 years ago