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2 years ago

Multiple Choice

Chemistry

2 answers:

Georgia [21]2 years ago

7 0

Answer:

A.- maintaining a positive attitude

Explanation:

The answer is very obvious you need to maintain a positive attitude while studying.

azamat2 years ago

3 0

Answer:

A: maintaining a positive attitude

Explanation:

I myself have personal experience with all of these, and B,C,D just don´t seem like reasonable answers. If you wait until the last minute to start an assignment, chances are you won´t get it done. Listening to the television while studing is a pretty bad idea because you might get distracted. Never study when tired because if you´re tired the information might not stick in your head. The only answer left is A.

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The chemical equation shows iron(III) phosphate reacting with sodium sulfate. 2FePO4 + 3Na2SO4 Fe2(SO4)3 + 2Na3PO4 What is the t

slava [35]

Answer: The theoretical yield of iron(III) sulfate is 26.6 grams

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Given mass of iron(III) phosphate = 20.00 g

Molar mass of iron(III) phosphate = 150.82 g/mol

Putting values in equation 1, we get:

$\text{Moles of iron(III) phosphate}=\frac{20g}{150.82g/mol}=0.133mol$

The given chemical equation follows:

$2FePO_4+3Na_2SO_4\rightarrow Fe_2(SO_4)_3+2Na_3PO_4$

As, sodium sulfate is present in excess. So, it is considered as an excess reagent.

Thus, iron(III) phosphate is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

2 moles of iron(III) phosphate produces 1 mole of iron(III) sulfate

So, 0.133 moles of iron(III) phosphate will produce = $\frac{1}{2}\times 0.133=0.0665moles$ of iron(III) sulfate

Now, calculating the mass of iron(III) sulfate from equation 1, we get:

Molar mass of iron(III) sulfate = 399.9 g/mol

Moles of iron(III) sulfate = 0.0665 moles

Putting values in equation 1, we get:

$0.0665mol=\frac{\text{Mass of iron(III) sulfate}}{399.9g/mol}\\\\\text{Mass of iron(III) sulfate}=(0.0665mol\times 399.9g/mol)=26.6g$

Hence, the theoretical yield of iron(III) sulfate is 26.6 grams

8 0

3 years ago

Suppose of nickel(II) chloride is dissolved in of a aqueous solution of potassium carbonate. Calculate the final molarity of chl

stich3 [128]

Answer: Molarity of chloride anion = 0.32 M

Note: the question is missing some values. The full question is given below;

Suppose 7.26 g of nickel(II) chloride is dissolved in 350 mL of a 0.50 M aqueous solution of potassium carbonate. Calculate the final molarity of chloride anion in the solution. You can assume the volume of the solution doesn't change when the nickel(II) chloride is dissolved in it. Be sure your answer has the correct number of significant digits.

Explanation:

Molarity or molar concentration is the number of moles (mol) of component per volume (liters) concentration of solution in mol/L or M

The mass of nickel (II) chloride is 7.26 g.

The volume of potassium carbonate is 350 mL = 0.35 L

The molarity of potassium carbonate solution is 0.50 M

The reaction of nickel (II) chloride and potassium carbonate is given below.

NiCl₂(aq) + KCO₃(aq) --------> KCl(aq) +NiCO₃(s)

The dissociation of nickel (II) chloride is given below.

NiCl₂ -----> Ni²⁺ + 2Cl⁻

The molar mass of nickel (II) chloride is 129.6 g/mol

The moles of nickel (II) chloride can be calculated by the formula given below;

No of moles = mass(g) / molar mass (g/mol)

No of moles = 7.26 / 129.6 = 0.056 moles

Therefore, molarity of NiCl₂ = 0.056 moles/ 0.35 L = 0.16 M

The molarity of 1 mole nickel (ii) chloride is 0.16 m and according to dissociation of nickel (II) chloride, 1 mole of nickel (II) chloride gives 2 moles of chloride anion.

Therefore, the molarity of chloride anion = 0.16 * 2 = 0.32 M

3 0

2 years ago

An ion with six protons, seven neutrons, and a charge of 2+ has an atomic number of ________.

Varvara68 [4.7K]

There are some standard numbers that help us describe the structure of an atom and help us categorize them. Those are the atomic number, the mass number and the numbers of electrons in an atom (or ion). Atoms are electrically neutral, hence they have the same number of protons as electrons. If an atom has a charge and has thus become an ion, it is because electrons joined it or left. For example in this case, since the ion has +2 charge, 2 electrons left it and thus the ion has 4 electrons (2 electrons less than its protons). The mass number is the sum of the protons and neutrons of an atom (that are in the nucleus). In this case, this yields a mass number of 13 for this ion. The atomic number of an atom (or ion) is the total number of protons in the nucleus. Protons do not leave the nucleus except for radioactive reactions and thus the atomic number of an atom (or ion) does not change in chemical reactions. In this case, the ion has an atomic number of 6.

3 0

3 years ago

Carbon has two naturally occurring isotopes: C-12 (natural abundance is 98.93%) and C-13 (natural abundance is 1.07%). How many

Sav [38]

The number of atoms present, on average, will be the natural abundance of the isotope times the number of atoms in the sample => number of C-13 atoms = C-13 abundance * number of atoms in the sample = 1.07% * 30,000 = 1.07 * 30,000 / 100 = 321 atoms. Answer: 321 atoms.

5 0

3 years ago

A car traveling at a constant speed travels 175 miles in four hours. How many minutes will it take for the car to travel 1000 fe

elena-14-01-66 [18.8K]

It takes 0.26 minutes to travel 1000 feet

Solution:

Given that car traveling at a constant speed travels 175 miles in four hours

Distance = 175 miles

Time taken = 4 hours

Convert the units to feet and minute

Given that,

1 mile = 5280 feet

175 miles = 5280 x 175 feet = 918720 feet

Also we know that,

1 hour = 60 minutes

4 hours = 60 x 4 minutes = 240 minutes

Thus, we got,

Distance = 918720 feet

Time taken = 240 minutes

Find the speed of car

Speed is given by formula:

$speed = \frac{distance}{time}$

$speed = \frac{918720}{240} = 3828$

Thus speed of car is 3828 feet per minute

How many minutes will it take for the car to travel 1000 feet?

Let "x" be the minutes needed for 1000 feet

speed of car is 3828 feet per minute

1 minute = 3828 feet

x minute = 1000 feet

This forms a proportion. We can solve by cross multiplying

$x \times 3828 = 1000 \times 1\\\\x = \frac{1000}{3828}\\\\x = 0.26$

Thus it takes 0.26 minutes to travel 1000 feet

7 0

3 years ago