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3 years ago

How are the atomic number and the number of protons related to each other?

Chemistry

1 answer:

SpyIntel [72]3 years ago

5 0

Answer:

Neutral atoms of each element contain an equal number of protons and electrons. The number of protons determines an element's atomic number and is used to distinguish one element from another. ... Together, the number of protons and the number of neutrons determine an element's mass number.

Explanation:

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Define the law of conservation of charge and provide an example.

iren2701 [21]

Answer:

Conservation of Charge is the principle that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always conserved.

7 0

3 years ago

Calculate the number of milliliters of 0.710 M Ba(OH)2 required to precipitate all of the Mn2+ ions in 161 mL of 0.796 M KMnO4 s

USPshnik [31]

Answer: The volume of barium hydroxide is 183 mL.

Explanation:

To calculate the moles of cadmium nitrate, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$ .....(1)

Molarity of $MnSO_4$ = 0.796 M

Volume of $MnSO_4$ = 161 mL = 0.161 L (Conversion factor: 1 L = 1000 mL)

Putting values in equation 1, we get:

$0.796mol/L=\frac{\text{Moles of }MnSO_4}{0.161L}\\\\\text{Moles of }MnSO_4=0.13mol$

The chemical equation for the reaction of manganese sulfate and barium hydroxide follows:

$MnSO_4(aq.)+Ba(OH)_2(aq.)\rightarrow Mn(OH)_2(s)+BaSO_4(aq.)$

By Stoichiometry of the reaction:

1 mole of manganese sulfate reacts with 1 mole of barium hydroxide.

So, 0.13 moles of manganese sulfate will react with = $\frac{1}{1}\times 0.13=0.13mol$ of barium hydroxide

Now, calculating the volume of barium hydroxide by using equation 1, we get:

Moles of barium hydroxide = 0.13 moles

Molarity of barium hydroxide = 0.710 M

Putting values in equation 1, we get:

$0.710mol/L=\frac{0.13mol}{\text{Volume of barium hydroxide}}\\\\\text{Volume of barium hydroxide}=0.183L$

Converting this into milliliters, we use the conversion factor:

1 L = 1000 mL

So, $0.183L=0.183\times 1000=183mL$

Hence, the volume of barium hydroxide is 183 mL.

7 0

3 years ago

Which step of scientific inquiry involves organizing and interpreting the data?

elena-14-01-66 [18.8K]

b. Analysis. In the analysis step, you organize and interpret your data to see if they support your hypothesis.

a. Experimentation is incorrect because this is the step in which you do experiments to test if your prediction is accurate.

c. Conclusion is incorrect because a conclusion is a decision you make to accept or reject your hypothesis.

d. Hypothesis is incorrect because a hypothesis is a proposed explanation for why something happens.

8 0

3 years ago

What is the freezing point of a solution of 498mL of water (solute) dissolved in 2.50 L of ethanol (solvent), C2H5OH? The densit

jok3333 [9.3K]

Answer:

Freezing T° of solution is -142.4°C

Explanation:

This excersise is about colligative properties, in this case freezing point depression,

ΔT = Kf . m . i

Where ΔT = Freezing T° of solvent - Freezing T° of solution

Kf = Cryoscopic constant

m = mol/kg (molality)

i = Number of ions dissolved.

Water is not ionic, so i = 1

Let's find out m.

We determine mass of water, by density

498ml . 1 g/mL = 498 g

We convert the mass of water to moles → 498 g . 1mol/18g = 27.6 moles

We determine mass of solvent by density

2500 mL . 0.789 g/mL = 1972.5 g

Notice, we had to convert L to mL to cancel units.

1 cm³ = 1 mL

We convert the mass from g to kg → 1972.5 g . 1kg /1000g = 1.97kg

We determine m = mol/kg → 27.6mol / 1.97kg = 13.9 m

Kf for ethanol is: 1.99 °C/m

Freezing T° for ethanol is: -114.6°C

We replace at formula: - 114.6°C - Freezing T° solution = 1.99 °C/m . 13.9 m . 1

- 114.6°C - Freezing T° solution = 27.8 °C

- Freezing T° solution = 27.8°C + 114.6°C

Freezing T° Solution = - 142.4 °C

7 0

2 years ago

If the volume of the original sample in Part A ( P1 = 242 torr , V1 = 27.0 L ) changes to 80.0 L , without a change in the tempe

Brrunno [24]

The new pressure is 81.675 torr

Since temperature and moles are held constant, we use Boyle's Law:

A gas law known as Boyle's law asserts that a gas's pressure is inversely proportional to its volume when it is held at a fixed temperature and of a given mass.

To put it another way, as long as the temperature and volume of the gas remain constant, the pressure and volume of the gas are inversely proportional to one another.

The Anglo-Irish chemist Robert Boyle proposed Boyle's law in the year 1662.

P1V1=P2V2. Simply plug in your values. The units can remain in torr. Converting to atmospheres is not needed.

(242 torr)(27.0 L)=P2(80.0 L)

P2=[(242)(27)]/80 = 81.675 torr

Hence The new pressure is 81.675 torr

Learn more about Boyle's Law here

brainly.com/question/26040104

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3 0

1 year ago