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Sati [7]
2 years ago
11

Why must sample spots be above the solvent in paper chromatography

Chemistry
1 answer:
marishachu [46]2 years ago
6 0
Because if they are submerged in the solvent, they would dissolve! This would prevent them from seperating and not allow you to actually record anything
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Two solutions are made by mixing sugar and enough water to make a 1 liter solution. One contains 10% sugar and the other 20% sug
zysi [14]

Two solutions are made by mixing sugar and enough water to make a 1 liter solution. 10% sugar has more solvent.

In chemistry, a solution is a homogeneous mixture of two or more compounds in their relative proportions that can be continually altered up to what is referred to as the limit of solubility. Although the word "solution" is frequently used to refer to the liquid state of matter, solutions of gases and solids are also possible. A solute is dissolved by a solvent (s), which is a substance (from the Latin solv, "loosen, untie, solve,") to produce a solution. The most common form of a solvent is a liquid, although other forms include solids, gases, and supercritical fluids. Depending on the temperature, a different amount of solute can dissolve in a given volume of solvent. Solvents are extensively utilized in paints, paint removers, inks, and dry cleaning.

Learn more about solution here :

brainly.com/question/7932885

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7 0
1 year ago
Chất có ở đâu ? nước tự nhiên là chất hay hỗn hợp
Lynna [10]

Answer:

Water, H2O, is a pure substance, a compound made of hydrogen and oxygen. Although water is the most abundant substance on earth, it is rarely found naturally in its pure form. Most of the time, pure water has to be created. Pure water is called distilled water or deionized water.

4 0
3 years ago
PLEASE HELP ME NOW I NEED HELP What will happen if a single crystal is introduced into a super-saturated solution? a. The crysta
Klio2033 [76]

Answer:

c

It excess out the crystal

4 0
3 years ago
A useful single-displacement reaction involves thermite, which is a
Licemer1 [7]
The reaction of iron (III) oxide and aluminum is initiated by heat released from a small amount "starter mixture". This reaction is an oxidation-reduction reaction, a single replacement reaction, producing great quantities of heat (flame and sparks) and a stream of molten iron and aluminum oxide which pours out of a hole in the bottom of the pot into sand.

The balanced chemical equation for this reaction is:

2 Al(s) + Fe2O3(s) --> 2Fe(s) + Al2O3(s) + 850 kJ/mol

Curriculum Notes
This chemical reaction can be used to demonstrate an exothermic reaction, a single replacement or oxidation-reduction reaction, and the connection between ∆H calculated for this reaction using heats of formation and Hess' Law and calculating ∆H for this reaction using qrxn = mc∆T and the moles of limiting reactant. This reaction also illustrates the role of activation energy in a chemical reaction. The thermite mixture must be raised to a high temperature before it will react.

To determine how much thermal energy is released in this reaction, heats of formation values and Hess' Law can be used.

By definition, the deltaHfo of an element in its standard state is zero.

2 Al(s) + Fe2O3(s) --> 2Fe (s) + Al2O3 (s)

The deltaH for this reaction is the sum of the deltaHfo's of the products - the sum of the deltaHfo's of the reactants (multiplying each by their stoichiometric coefficient in the balanced reaction equation), i.e.:

deltaHorxn = (1 mol)(deltaHfoAl2O3) + (2 mol)(deltaHfoFe) - (1 mol)(deltaHfoFe2O3) - (2 mol)(deltaHfoAl)

deltaHorxn = (1 mol)(-1,669.8 kJ/mol) + (2 mol)(0) - (1 mol)(-822.2 kJ/mol) - (2mol)(0 kJ/mol)

deltaHorxn = -847.6 kJ

The melting point of iron is 1530°C (or 2790°F).
MARK ME BRAINLIEST

7 0
2 years ago
Day and night are caused by what
Aleks04 [339]

Answer:

THE GOD ALMIGHTY!

Explanation:

6 0
3 years ago
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