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2 years ago

1. The emission spectrum of mercury atoms has a bright green line with wavelength

1 answer:

5 0

Emission spectrum results from the movement of an electron from a higher to a lower energy level. The frequency of the photon is 5.5 * 10^14 Hz.

From the formula;

E = hc/λ

h = Plank's constant = $6.6 * 10^-34$ Js

c = speed of light= $3 * 10^8$

λ = wavelength = $546.1 * 10^-9$ m

E = $6.6 * 10^-34 * 3 * 10^8/546.1 * 10^-9$

E = $3.63 * 10^-19$ J

Also;

E =hf

Where;

h = Planks's constant

f = frequency of photon

f = E/h

f = $3.63 * 10^-19 J/6.6 * 10^-34$

f = $5.5 * 10^14$ Hz

Learn more: brainly.com/question/18415575

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A person suffering from hyponatremia has a sodium ion concentration in the blood of 0.116 M and a total blood volume of 4.7 L .

klemol [59]

Explanation:

Normal moles of $Na^{+}$ = volume × normal concentration

= 4.7 × 0.139 = 0.6533 mol

Moles of $Na^{+}$ in hyponatremia blood = volume × hyponatremia concentration

= 4.7 × 0.116 = 0.5452 mol

Moles of NaCl to be added = moles of extra $Na^{+}$ needed

= 0.6533 mol - 0.5452 mol = 0.1081 mol

Mass of NaCl = moles × molar mass of NaCl

= 0.1081 mol × 58.443

= 6.317g

= 6.32 g (approx)

Thus, we can conclude that mass of sodium chloride would need to be added to the blood is 6.32 g.

3 0

3 years ago

What explanation accounts for the observation that the mass of the products in reaction #1 (open system) were not equal?

Anna007 [38]

Answer:

The law of conservation of mass states that matter can not be created or destroyed in a chemical reaction.

Explanation:

5 0

2 years ago

Question 2 of 5

alex41 [277]

Precision relates to how close the answers are to each other, so I’d think it would be D because of the limited range between data points.

7 0

3 years ago

Read 2 more answers

What is the pH of an acidic solution?

tiny-mole [99]

The answer is A, between 0 and 7.

In a pH scale from 0 to 14, we can groups these numbers into acidic, neutral, and alkaline. 7 is the neutral pH value, therefore, 0-7 is always acidic, and 7-14 is alkaline.
The smaller the number is, the more acidic the solution will be. This applies same in alkalis, the larger the pH value is, the more alkaline the solution is.

We can measure the pH of solution with many methods, the easiest way include using a pH paper, more advanced and accurate methods includes using a pH meter.

6 0

2 years ago

A reaction of 41.9 g of Na and 30.3 g of Br2 yields 36.4 g of NaBr . What is the percent yield?

Licemer1 [7]

Answer: The percent yield is, 93.4%

Explanation:

First we have to calculate the moles of Na.

$\text{Moles of Na}=\frac{\text{Mass of Na}}{\text{Molar mass of Na}}=\frac{41.9g}{23g/mole}=1.82moles$

Now we have to calculate the moles of $Br_2$

${\text{Moles of}Br_2} = \frac{\text{Mass of }Br_2 }{\text{Molar mass of} Br_2} =\frac{30.3g}{160g/mole}=0.189moles$

${\text{Moles of } NaBr} = \frac{\text{Mass of } NaBr }{\text{Molar mass of } NaBr} =\frac{36.4g}{103g/mole}=0.353moles$

The balanced chemical reaction is,

$2Na(s)+Br_2(g)\rightarrow 2NaBr$

As, 1 mole of bromine react with = 2 moles of Sodium

So, 0.189 moles of bromine react with = $\frac{2}{1}\times 0.189=0.378$ moles of Sodium

Thus bromine is the limiting reagent as it limits the formation of product and Na is the excess reagent.

As, 1 mole of bromine give = 2 moles of Sodium bromide

So, 0.189 moles of bromine give = $\frac{2}{1}\times 0.189=0.378$ moles of Sodium bromide

Now we have to calculate the percent yield of reaction

$\%\text{ yield}=\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100=\frac{0.353 mol}{0.378}\times 100=93.4\%$

Therefore, the percent yield is, 93.4%

3 0

3 years ago