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3 years ago

The step that usually comes last in solving numeric problems is to

Chemistry

1 answer:

Novosadov [1.4K]3 years ago

4 0

that answer is incorrect.... the answer is evaluate. The 3 steps are, analyze, calculate, evaluate.

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The strongest substance in your body is:

Sholpan [36]

The enamel is the strongest substance in our bodies mainly inside your mouth.

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4 years ago

Does granulated sugar dissolve in water faster than sugar cubes?

Mariulka [41]

Granulated sugar dissolves faster than a sugar cube since it has a higher surface area. A sugar cube has a low surface which takes more time to dissolve.

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4 years ago

What kind of oxide is formed when a piece of sodium is dropped in the water

aleksley [76]

Answer:

Sodium oxide is the product

Explanation:

4Na+O2->2Na2O

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3 years ago

A 3.96x10^-24 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000-cm cuvet; a blank solution containi

viktelen [127]

Actual question from source:-

A 3.96x10-4 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000 cm cuvette. A blank had an absorbance of 0.029. The absorbance of an unknown solution of compound A was 0.375. Find the concentration of A in the unknown.

Answer:

Molar absorptivity of compound A = $1502.53\ {Ms}^{-1}$

Explanation:

According to the Lambert's Beer law:-

$A=\epsilon l c$

Where, A is the absorbance

l is the path length

$\epsilon$ is the molar absorptivity

c is the concentration.

Given that:-

c = $3.96\times 10^{-4}\ M$

Path length = 1.000 cm

Absorbance observed = 0.624

Absorbance blank = 0.029

A = 0.624 - 0.029 = 0.595

So, applying the values in the Lambert Beer's law as shown below:-

$0.595=\epsilon\times 1.000\ cm\times 3.96\times 10^{-4}\ M$

$\epsilon=\frac{0.595}{3.96\times 10^{-4}}\ {Ms}^{-1}=1502.53\ {Ms}^{-1}$

<u>Molar absorptivity of compound A = $1502.53\ {Ms}^{-1}$ </u>

4 0

4 years ago

What is the percent by mass of nahco3 in a solution containing 10 g of nahco3 dissolved in 400 ml of h2o?

Marat540 [252]

Answer is: the percent by mass of NaHCO₃ is 2,43%.
m(NaHCO₃) = 10 g.
V(H₂O) = 400 ml.
d(H₂O) = 1 g/ml.
m(H₂O) = V(H₂O) · d(H₂O).
m(H₂O) = 400 ml · 1 g/ml.
m(H₂O) = 400 g.
m(solution) = m(H₂O) + m(NaHCO₃).
m(solution) = 400 g + 10 g.
m(solution) = 410 g.
ω(NaHCO₃) = 10 g ÷ 410 g · 100%.
ω(NaHCO₃) = 2,43 %

7 0

3 years ago