All categories

2 years ago

How much calcium can be recovered from 75.0g of calcium fluoride

Chemistry

1 answer:

7nadin3 [17]2 years ago

3 0

38.46g

Explanation:

Given parameters:

Mass of CaF₂ = 75.0g

Unknown:

Mass of calcium that can be recovered = ?

Solution:

This is a mass percentage problem and we need to solve it accordingly.

To solve this problem;

Find the molar mass of CaF₂

Find the ratio between the molar mass of Ca and that of CaF₂

Multiply by the given mass

Molar mass of CaF₂ = 40 + (2 x 19) = 78g/mol

Mass of calcium = $\frac{40}{78}$ x 75 = 38.46g

learn more:

Mass percentage brainly.com/question/8170905

#learnwithBrainly

You might be interested in

Which is the best way to represent 0.0035 kg by using scientific notation?

Zolol [24]

The answer is 3.5 × 10^-3

7 0

2 years ago

Help help help ASFAP

gulaghasi [49]

Answer:

A directory of relatives' phone numbers

Hope this helps

Explanation:

5 0

2 years ago

1Which is a dopant for a p-type semiconductor?

aalyn [17]

For a p type of semiconductor we need a dopant which is from 13th group in periodic table

Al , B, Ga, In Tl

So the correct element will be In : Indium

The other elements belongs to 15th group and hence will give n type semiconductor

5 0

3 years ago

Read 2 more answers

A. Identify the steps of the scientific method?

DedPeter [7]

Answer:

1. The steps of the scientific method consist of seven things: Ask a question, get the research needed for a experiment, (What are you trying to find out? What materials do I need to complete the experiment? What are the procedures needed to complete the experiment?) create a hypothesis, (your educated guess on what you think the results of the experiment will be) conduct a experiment (complete multiple different trials preferably three) to test your hypothesis, make observations and record data during the experiment, draw a conclusion, (Was your hypothesis correct? Yes or no and explain why it is wrong or right) present your findings.

2. A hypothesis is a educated guess that the scientist believe will be the answer at the end of the experiment which is why they conduct a experiment in the first place to find viable data that will support their hypothesis.

3. Predictions consist of theories that will test the hypothesis (educated guess) because they're the reasoning to why you believe your guess is correct.

4. A control group consists of variables that do not go through change during a experiment, things that remain the same.

5. Data can be presented in many different ways in the form of graphs, charts, or a research paper. You find the data by completing multiple different trials in a experiment, to make sure you have valid results to write down in your data research.

6. Remember that your hypothesis is your educated guess at the beginning of the experiment, what YOU thought was going to happen during the experiment and if the data you received during the experiment supports your hypothesis.

7. Your procedures, perhaps you measured a variable wrong, perhaps you used to much, or to little of a variable, all depends on your experiment.

8. Having people review and test your data by conducting their own experiments will not only make sure that your data is valid but it insures you even more of your conclusion, making it more accepted by other scientists.

Hope this helps.

4 0

2 years ago

Use lewis theory to determine the formula for the compound that forms between sr and se

katen-ka-za [31]

$\text{Sr}\text{Se}$

<h3>Explanation</h3>

The Lewis Theory predicts the way atoms form bond based on their numbers of valence electrons. Atoms gain or lose electrons as they seek to achieve either a complete eight-electron valence shell or an empty shell, exposing the inner eight-electron shell. Both electron configurations are stable and are known as "octets". However, atoms tend to prefer the configuration with the minimum number of electron transfers.

Strontium (Sr) is found in group 2 (II A) of a modern periodic table. A neutral atom of strontium has two valence electrons in its valence shell.

Selenium (Se) is found in group 16 (VI A) of a modern periodic periodic table. A neutral atom of selenium contains six electrons in its valence shell.

Strontium needs to either lose two electrons or gain six electrons to achieve a configuration with eight electrons in its valence shell. Losing two electrons take less energy. Strontium is thus expected to lose two electrons.

Similarly, selenium would prefer gaining two electrons to losing six electrons. It is expected to gain two electrons.

As a result, a strontium atom would supply exactly two electrons. At the same time, a As a result, a selenium atom would accept the two electrons, no more or no less. The two elements would combine at a one to one ratio. In other words:

$n(\text{Sr, atoms}) : n(\text{Se, atoms}) \\= n(\text{Sr, electrons lost}) : n(\text{Se, electrons gained}) \\= 1:1$

Each electron carries one negative charge. As a result, atoms that have gained electrons demonstrate a negative charge, whereas atoms that have lost electrons appear to be positive. By convention, atoms with a positive charge shall be written in front of those with a negative charge in a formula.

Sr atoms have lost electrons. Accordingly, they carry positive charges and shall be written at the beginning of the formula.

Se atoms have gained electrons. Accordingly, they carry negative charges and shall be placed to the end of the formula.

Thus the chemical formula: $\text{Sr}\text{Se}$

4 0

3 years ago