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3 years ago

Please help I’ll mark brainliest!

Chemistry

2 answers:

IRISSAK [1]3 years ago

8 0

I believe you got the correct answer D.

I actually looked up the problem on quizlet. It reads, “because each element has a different set of emission colors from the emission spectrum. They have different energy level spacing and when the electrons get excited, they go to different energy levels because of the different spacing.”

If u want to view where I got this answer from, go to quizlet and type up Flame Test Lab. There should be 8 terms in the set.

Anyways, I hope that this helps! Have a wonderful day :)

Anni [7]3 years ago

6 0

Answer:

D because excited electrons fall back.....

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Consider the reaction.

Alekssandra [29.7K]

Answer:The correct answer is option C.

Explanation:

$N_2(g)+3H_2(g)\rightarrow 2NH_3(g)$

At STP, 1 mol of gas occupies 22.4 L of volume

So, 100.0 L volume of $NH_3$ will be occupied by :

$\frac{1}{22.4 L}\times 100.0 L=4.4642 moles$

According to reaction 2 moles $NH_3$ are obtained from 1 mole of $N_2$ .

Then,4.4642 moles of $NH_3$ will be obtained from :

$\frac{1}{2}\times 4.4642$ that is 2.2321 moles of $N_2$

Mass of $N_2$ gas:

Moles of $N_2$ gas Molar mass of $N_2$ gas:

$2.2321 mol\times 28 g/mol=62.4988\approx 62.50 g$

Hence, the correct answer is option C.

4 0

3 years ago

Read 2 more answers

A ray of yellow light has a wavelength of about 5.8×10−7 m. Will exposure to yellow light cause electrons to be emitted from ces

Dima020 [189]

Given the wavelength of the yellow light (700 nm. in this case) we can find the frequency
by dividing the speed of light c by the wavelength w, that is: f = c/w and we know that 
c is equal to 2.998 * 10**8 meters per second. 
So the frequency f = (2.998 * 10**8) / (7.0 * 10**-7) = 4.283 * 10**14 cycles per sec. 
(or Hz.) Since the threshold frequency of Cs is 9.39 * 10**14 Hz, the red light doesn't 
have a high enough frequency (or energy) to cause electron emission. 
Hope this answers your question.

8 0

3 years ago

This is a sign of a chemical reaction that involves a new color being created during the reaction.

svetoff [14.1K]

Hey there!

When two or more substances combine, they create one or more new substances, which sometimes have different molecular structures from the original substances, meaning they absorb and radiate light in different ways, leading to a color change.

Hope this helps! :)

5 0

3 years ago

1) What mass of Na2CO3 is required to make 50cc of its seminormal solution?

love history [14]

Answer:

$m=1.325gNa_2CO_3$

Explanation:

Hello,

In this case, by considering the given seminormal solution, we infer it is a 0.5-N solution which means that we can obtain the equivalent grams as shown below for the 55 cc (0.055 L) volume:

$eq-g=0.5eq-g/L*0.050L=0.025eq-g$

Next, since sodium carbonate has two sodium ions with a +1 oxidation state each, we can obtain the moles:

$mol=0.025eq-gNa_2CO_3*\frac{1molNa_2CO_3}{2eq-gNa_2CO_3}\\ \\mol=0.0125molNa_2CO_3$

Finally, the mass is computed by using its molar mass (106 g/mol)

$m=0.0125molNa_2CO_3*\frac{106gNa_2CO_3}{1molNa_2CO_3} \\\\m=1.325gNa_2CO_3$

Regards.

7 0

3 years ago

How many grams of Na2CO3 must be dissolved into 155g of water to create a solution with a molarity of 8.20 mol/kg

zhannawk [14.2K]

Answer:

135g Na2CO3

Explanation:

I'm going to assume you mean Molality which is mol solute/kg solvent

Molarity would be mol soute/ L solution

we know we have 155g of water which is .155 kg

essentially we have the equation:

mol/kg = 8.20

we substitute .155 in for kg and get:

mol/.155 = 8.20

Solving this gives mol = 1.271

now we must convert to grams using the molar mass

Molar mass Na2CO3 = 106G/mol

so to cancel moles we multiply:

1.271mol x 106g/mol

= 135g

4 0

2 years ago