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4 years ago

Which one of the following is an attribute for an extracting solvent?

Chemistry

1 answer:

PSYCHO15rus [73]4 years ago

7 0

Answer:

The answer is B

[The extracting solvent should be non-toxic and readily available]

Explanation:

The extracting solvent should not pose a risk to life (or the risk have to be minimum) and be available in large quantity.

A. Most of the extracting solvents are volatile, and is a good think because you can remove them by distillation.

C. The extraction solvent should not react with the solute, because you lose the extracted compound.

D. The extraction solvent should not be miscible with water. Usually you extract compounds organic compounds from water using an appropriate extracting solvent.

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Drag the item from the idea bank to its corresponding match

babymother [125]

Hope this is helpful

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3 years ago

How is it possible for there to be more than one kind of atom of the same element?

tiny-mole [99]

They are called isotopes.

Isotopes have the same number of electrons and protons in their unionized state. They differ in the number of neutrons. The first and simplest example is hydrogen.

The most common hydrogen has

1 proton

1 electron and

0 neutrons

It has 2 cousins

1 proton

1 electron

1 neutron

And

1 proton

1 electron

2 neutrons.

Most elements have some differences in the number of neutrons present in their nuclei. Cesium and Xenon have the most number of isotopes. Each has 36. You wonder how the atoms are held together.

6 0

3 years ago

Read 2 more answers

Calculate the molarity of a solution obtained dissolving 10.0 g of cobalt(Ⅱ) bromide tetrahydrate in enough water to make 450 mL

Vladimir [108]

Answer:

The molarity of the CoBr2•4H2O solution is 7.64 × 10-2 M

Explanation:

Cobalt (II) bromide tetrahydrate

• Cobalt - A transition metal with Roman numeral (II) → charge: +2 → Co2+

• Bromide - anion from group 7A → -1 charge → symbol: Br-

• Tetrahydrate- tetra- means 4 and hydrate is H2O

The chemical formula of the compound is: CoBr2•4H2O

We then need to determine the number of moles of CoBr2•4H2O since this is the only information missing for us to find molarity. Notice that the volume of the solution is already given.

We’re given the mass of CoBr2•4H2O. We can use the molar mass of CoBr2•4H2O4 to find the moles.

•The molar mass of CoBr2•4H2O is:

CoBr2•4H2O

1 Co x 58.93 g/mol Co = 58.93 g/mol

2 Br x 79.90 g/mol Br = 159.80 g/mol

8 H x 1.008 g/mol H = 8.064 g/mol

4 O x 16.00 g/mol O = 64.00 g/mol

________________________________________

Sum = 290.79 g/ mo

The moles of CoBr2•4H2O is:

= 10.0 g CoBr2•4H2O x $\frac{ 1 mol CoBr_2 . 4H_2O}{290.79 g CoBr_2 . 4H_2O}$

= 0.0344 mol CoBr2•4H

We know that the volume of the solution is 450 mL.

We can now calculate for molarity:

Convert mL to L → 1 mL = 10-3 L

Formula:

Molarity (M)= Mole of solute / Liters of solution

= 0.0344 mol CoBr2•4H / 450 mL x 1 ml / 10^ -3 L

= 0.0764

= 7.64 × 10-2 mol/L

8 0

3 years ago

A large cyclotron directs a beam of He++ nuclei onto a target with a beam current of 0.250 mA. (a) How many He++ nuclei per seco

nikitadnepr [17]

Answer:

a. 7.8*10¹⁴ He⁺⁺ nuclei/s

b. 4000s

c. 7.7*10⁸s

Explanation:

I = 0.250mA = 2.5 * 10⁻³A

Q = 1.0C

1 e- contains 1.60 * 10⁻¹⁹C

But He⁺⁺ Carrie's 2 charge = 2 * 1.60*10⁻¹⁹C = 3.20*10⁻¹⁹C

(A).

No. Of charge per second = current passing through / charge

1 He⁺⁺ = 2.50 * 10⁻⁴ / 3.2*10⁻¹⁹C

1 He⁺⁺ = 7.8 * 10¹⁴ He⁺⁺ nuclei

(B).

I = Q / t

From this equation, we can determine the time it takes to transfer 1.0C

I = 1.0 / 2.5*10⁻⁴ = 4000s

(C).

Time it takes for 1 mol of He⁺⁺ to strike the target =?

Using Avogadro's ratio,

1.0 mole of He = (6.02 * 10²³ ions/mol ) * (1 / 7.81*10¹⁴ He ions)

Note : ions cancel out leaving the value of the answer in mols.

1.0 mol of He = 7.7 * 10⁸s

8 0

3 years ago

Write down five things that you personally could do in your day-to-day life to help with the problem of climate change. Write do

beks73 [17]

Before that, we need to know what causes climate change. One of the main reasons are the carbon dioxide released into the atmosphere, it traps heat but allow more heat to enter the earth, therefore climate increases over the years.

1. Set air conditioner to a higher temperature (eg. 25°C) or turn on fans instead.
Operating AC can use a lot of energy, and these energy is produced by burning if fossil fuels which releases carbon dioxide.

2. Take public transports instead of cars. The more private cars there are, the more pollutants it release, these pollutants includes carbon dioxide.

3. Turn off all the lights / electrical appliances when we leave a place. Again, electrical appliances require energy which is produced by burning of fossil fuels that gives out carbon dioxide.

4. Recycle and reuse paper that is only used on one side. Papers are extracted from trees and one main function of trees is to absorb carbon dioxide from the air. If many trees are cut, the amount of carbon dioxide in air would increase.

5. Do the laundry only if you have clothes full for the machine. If the washing machine is not full and you're starting it up, it really uses a lot of energy and water, which all again it triggers the release of carbon dioxide.

4 0

4 years ago