Which substance is a mixtureWhich pure substance can be classified as an element

balandron [24]

$\huge\fbox{Answer ☘}$

It is given in the question that 200.0 grams of sodium hydroxide reacts with excess of sulphuric acid.

The given reaction is shown below

$\bold\blue{2NAOH + H _{2}SO _{4} \: - > 2H _{2} O+ NA _{2}SO_{4} }\\$

In this reaction, two mole of sodium hydroxide react with one mole of sulphuric acid to give two mole of water and one mole of sodium sulfate.

To determine the mass of sodium sulfate, first calculate the moles of sodium hydroxide as the value of mass is provided.

The molecular weight of NaOH is 40 g/mol.

The formula is shown below.

$\pink{n = \frac{m}{ M}}\\$

Where,

✫ n is the number of moles

✫ m is the mass

✫ M is the molecular weight

To calculate the number of moles, substitute the values in the above equation.

$\pink{n = \frac{200.0}{40g \: mol {}^{ - 1} } } \\ \\\pink{ ⇢n = 5}$

In the equation it is given that 2 mole of sodium hydroxide gives 1 mole of sodium sulphate.

So, to determine the actual mole of sodium sulfate divide the calculated moles of NaOH by 2.

$\pink{⇢ \frac{5}{2}} \\ \\ \pink{⇢ 2.5 \: mol}$

So 2.5 mol sodium sulfate is formed from 5 mol NaOH.

The molecular weight of sodium sulfate is 142.1 g/mol.

To calculate the mass of sodium sulfate, substitute the values in the formula.

$\pink{⇢2.5 = \frac{m}{142.1g \: mol {}^{ - 1} } } \\ \\\pink{ ⇢ m = 2.5 \times 142.1 }\\ \\ \pink{⇢ m = 355.25}$

Therefore, the mass of sodium sulfate formed when we start with 200.0 grams of sodium hydroxide and you have excess sulphuric acid is 355.25g.

hope helpful~

5 0

2 years ago

The graph below illustrates a change in energy during a phase change.

vagabundo [1.1K]

Answer:

Endothermic. Endothermic phase changes take in heat from the surrounding environment; they include melting, sublimation and boiling. ... For example, the forces that hold iron atoms together are strong, so it takes high temperatures to melt iron.

Explanation:

3 0

3 years ago

Read 2 more answers

The rate constant for a certain reaction is k = 4.50×10−3 s−1 . If the initial reactant concentration was 0.400 M, what will the

SIZIF [17.4K]

<u>Answer:</u> The concentration of reactant after the given time is 0.0205 M

<u>Explanation:</u>

Rate law expression for first order kinetics is given by the equation:

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$

where,

k = rate constant = $4.50\times 10^{-3}s^{-1}$

t = time taken for decay process = 11.0 min = 660 s (Conversion factor: 1 min = 60 s)

$[A_o]$ = initial amount of the reactant = 0.400 M

[A] = amount left after decay process = ?

Putting values in above equation, we get:

$4.50\times 10^{-3}s^{-1}=\frac{2.303}{660s}\log\frac{0.400}{[A]}$

$[A]=0.0205M$

Hence, the concentration of reactant after the given time is 0.0205 M

4 0

3 years ago

The water gained 900 J of energy, what was the energy change of the metal?

Gemiola [76]

Answer:

it lost 900J of energy I will assume and that would mean the change in energy is -900J

Explanation:

4 0

3 years ago

Under what pressure will a scientist need to store 0.400 miles of gas if the container has a volume of 200.0 mL and the temperat

mihalych1998 [28]

Hello!

Ok so for this problem we use the ideal gas law of PV=nRT and I take it that the scientist needs to store 0.400 moles of gas and not miles.

So if we have
n=0.400mol
V=0.200L
T= 23degC= 273k+23c=296k
R=ideal gas constant= 0.0821 L*atm/mol*k

So now we rearrange equation for pressure(P)

P=nRT/V
P=((0.400mol)*(0.0821 L*atm/mol*k)*(296k))/(0.200L) = 48.6 atm of pressure

Hope this helps you understand the concept and how to solve yourself in the future!! Any questions, please feel free to ask!! Thank you kindly!!!

4 0

3 years ago