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2 years ago

Use the portion of the periodic table shown below to answer the questions.

Chemistry

1 answer:

Bingel [31]2 years ago

4 0

The two elements that have the same properties as sodium are potassium and rubidium .

<h3>What is periodic table?</h3>

The periodic table is an arrangement of the elements in order of increasing atomic number.

From the list, the two elements that have the same properties as sodium are potassium and rubidium .

Proton has an atomic number of 20 and a mass number of 40. The number of electrons is the same as the number of protons. Given that the atomic number is the number of protons present, we have 20 electrons and 20 protons.

Number of neutrons = Mass number - Number of protons

= 40 - 20 = 20 neutrons

Learn more about periodic table:brainly.com/question/11155928

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A 35.0 mL sample of 1.00 M KBr and a 60.0 mL sample of 0.600 M KBr are mixed. The solution is then heated to evaporate water unt

Katarina [22]

Answer: The molarity of KBr in the final solution is 1.42M

Explanation:

We can calculate the molarity of the KBr in the final solution by dividing the total number of moles of KBr in the solution by the final volume of the solution.

We will first calculate the number of moles of KBr in the individual sample before mixing together

In the first sample:

Volume (V) = 35.0 mL

Concentration (C) = 1.00M

Number of moles (n) = C × V

n = (35.0mL × 1.00M)

n= 35.0mmol

For the second sample

V = 60.0 mL

C = 0.600 M

n = (60.0 mL × 0.600 M)

n = 36.0mmol

Therefore, we have (35.0 + 36.0)mmol in the final solution

Number of moles of KBr in final solution (n) = 71.0mmol

Now, to get the molarity of the final solution , we will divide the total number of moles of KBr in the solution by the final volume of the solution after evaporation.

Therefore,

Final volume of solution (V) = 50mL

Number of moles of KBr in final solution (n) = 71.0mmol

From

C = n / V

C= 71.0mmol/50mL

C = 1.42M

Therefore, the molarity of KBr in the final solution is 1.42M

5 0

2 years ago

The process of energy being captured

Amanda [17]

Answer:

Explanation:

I am not sure but I think it is B. Out of all the answers that one makes sense.

5 0

2 years ago

what is the formula used to find the heat energy for vaporization heat energy for fusion hrat energy for liquid

Alinara [238K]

Answer:

Use the formula q = m·ΔHv in which q = heat energy, m = mass, and ΔHv = heat of vaporization.

Explanation:

8 0

2 years ago

A saturated solution is made by dissolving 0.327 g of a polypeptide (a substance formed by joining together in a chainlike fashi

faust18 [17]

Answer: The approximate molecular mass of the polypeptide is 856 g/mol

Explanation:

To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

$\pi=iMRT$

Or,

$\pi=i\times \frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Volume of solution in L)}}\times RT$

where,

$\pi$ = osmotic pressure of the solution = 4.19 torr

i = Van't hoff factor = 1 (for non-electrolytes)

Mass of solute (polypeptide) = 0.327 g

Volume of solution = 1.70 L

R = Gas constant = $62.364\text{ L.torr }mol^{-1}K^{-1}$

T = temperature of the solution = $26^oC=[273+26]K=299K$

Putting values in above equation, we get:

$4.19torr=1\times \frac{0.327}{\text{Molar mass of solute}\times 1.70}\times 62.364\text{ L.mmHg }mol^{-1}K^{-1}\times 299K\\\\\text{molar mass of solute}=856g/mol$

Hence, the molar mass of the polypeptide is 856 g/mol

8 0

3 years ago

A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass

Alex

Answer:

Mass = 0.000176 gram

Steps:

m = V × ρ

= 20 milliliter × 8.8 gram/cubic meter

= 2.0E-5 cubic meter × 8.8 gram/cubic meter

= 0.000176 gram

Explanation:

8 0

3 years ago