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3 years ago

Tri

Chemistry

1 answer:

Phantasy [73]3 years ago

3 0

Answer:

If you touch the knob of a positively charged electroscope with another positively charged object,the leaves of the electroscope would remain apart.

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In beta decay, what is emitted?

stiks02 [169]

In beta minus (β−) decay, a neutron is converted to a proton and the process creates an electron and an electron antineutrino; while in beta plus (β+) decay, a proton is converted to a neutron and the process creates a positron and an electron neutrino. β+ decayis also known as positron emission.

5 0

3 years ago

A certain liquid has a normal boiling point of and a boiling point elevation constant . A solution is prepared by dissolving som

jek_recluse [69]

The question is incomplete, the complete question is:

A certain substance X has a normal freezing point of $-6.4^oC$ and a molal freezing point depression constant $K_f=3.96^oC.kg/mol$ . A solution is prepared by dissolving some glycine in 950. g of X. This solution freezes at $-13.6^oC$ . Calculate the mass of urea that was dissolved. Round your answer to 2 significant digits.

Answer: The mass of glycine that can be dissolved is $1.3\times 10^2g$

Explanation:

Depression in the freezing point is defined as the difference between the freezing point of the pure solvent and the freezing point of the solution.

The expression for the calculation of depression in freezing point is:

$\text{Freezing point of pure solvent}-\text{freezing point of solution}=i\times K_f\times m$

$\text{Freezing point of pure solvent}=\text{Freezing point of solution}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times w_{solvent}\text{(in g)}}$ ......(1)

where,

Freezing point of pure solvent = $-6.4^oC$

Freezing point of solution = $-13.6^oC$

i = Vant Hoff factor = 1 (for non-electrolytes)

$K_f$ = freezing point depression constant = $3.96^oC/m$

$m_{solute}$ = Given mass of solute (glycine) = ?

$M_{solute}$ = Molar mass of solute (glycine) = 75.07 g/mol

$w_{solvent}$ = Mass of solvent = 950. g

Putting values in equation 1, we get:

$-6.4-(-13.6)=1\times 3.96\times \frac{m_{solute}\times 1000}{75.07\times 950}\\\\m_{solute}=\frac{7.2\times 75.07\times 950}{1\times 3.96\times 1000}\\\\m_{solute}=129.66g=1.3\times 10^2g$

Hence, the mass of glycine that can be dissolved is $1.3\times 10^2g$

5 0

3 years ago

What are the angles in a 30°−60°−90° triangle after it is rotated clockwise 45°?

mina [271]

Angles do not change they can only rotate in a circular motion if the angles in a 30°−60°−90° triangle after it is rotated clockwise at 45°.

<h3>What are the angles?</h3>

The angles are the distance between two lines that are attached at one point and they can vary in shapes like triangle and square or circle and rectangle.

The square has the handle of equality for all the sides rectangle has two opposite side angles equal and the circle It has only one angle triangle consisting of 3 angles which are fixed and cannot be changed.

Therefore, if the angles in a 30°−60°−90° triangle after it is rotated clockwise at 45°Angles do not change they can only rotate in a circular motion.

Learn more about angles, here:

brainly.com/question/14569348

#SPJ2

3 0

1 year ago

Read 2 more answers

In a blast furnace, iron(III) oxide is used to produce iron by the following (unbalanced) reaction: Fe2O3 + CO---------->Fe +

rewona [7]

Answer:

a) The no. of moles of CO are needed = 75.15 mol.

b) The no. of moles of Fe are produced = 50.1 mol.

The no. of moles of CO₂ are needed = 75.15 mol.

Explanation:

Firstly, we need to write the balanced reaction:

Fe₂O₃ + 3CO → 2Fe + 3CO₂,

It is clear that 1 mol of Fe₂O₃ reacts with 3 mol of CO to produce 2 mol of Fe and 3 mol of CO₂.

a) If 4.00 kg Fe₂O₃ are available to react, how many moles of CO are needed?

We need to calculate the no. of moles of 4.00 kg Fe₂O₃:

n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.

Using cross multiplication:

1 mol of Fe₂O₃ need → 3 mol of CO to react completely, from stichiometry.

25.05 mol of Fe₂O₃ need → ??? mol of CO to react completely.

∴ The no. of moles of CO are needed = (3 mol)(25.05 mol)/(1 mol) = 75.15 mol.

b) How many moles of each product are formed?

To find the no. of moles of Fe formed:

Using cross multiplication:

1 mol of Fe₂O₃ produce → 2 mol of Fe, from stichiometry.

25.05 mol of Fe₂O₃ produce → ??? mol of Fe.

∴ The no. of moles of Fe are produced = (2 mol)(25.05 mol)/(1 mol) = 50.1 mol.

To find the no. of moles of CO₂ formed:

Using cross multiplication:

1 mol of Fe₂O₃ produce → 3 mol of CO₂, from stichiometry.

25.05 mol of Fe₂O₃ produce → ??? mol of CO₂.

∴ The no. of moles of CO₂ are needed = (3 mol)(25.05 mol)/(1 mol) = 75.15 mol.

4 0

3 years ago

PLEASE HELP WITH THESE THREE (30 POINTS)

olya-2409 [2.1K]

1. B
2. C
3. C

hope this helps

4 0

3 years ago