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2 years ago

4. Using your knowledge of elements, compounds

Chemistry

1 answer:

igor_vitrenko [27]2 years ago

4 0

Answer:

Element

magnesium, hydrogen, chlorine, sulfur

Compound

water, iron oxide

Mixture

air, salty water , dias cola.

Explanation:

Element is made up of only one type of atom and are relresented by symbols.

Compound are formed by chemical mixing of atoms of elements and have a chemical formula

Mixture are formed by simple mixing up of substances and mixture don't have chemical formula.

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Alcohol or acid will travel the furthest up the paper chromatography? pls help thanks and explain

d1i1m1o1n [39]

Answer:

True

Explanation:

Yes.

The distance that the molecules move depends on their solubility in the solvent and the size of the molecules. Heavy molecules will travel slower and therefore travel a shorter distance in the time the chromatography is run.

We know from such things as felt tip pens that colourings can be soluble in different solvents. Water soluble felt pens have colours that are - well - water soluble. Permanent felt pens have colours that are insoluble in water but that are soluble in another solvent. This could well be alcohol.

The water soluble colours may also be soluble in alcohol. The solubility in alcohol will be different from the solubility in alcohol, and so the Rf value ( the distance travelled) will also be different.

Because of the complicated shapes of the colours, the colours may not have the same order in the Rf values in the different solvents.

4 0

3 years ago

A student ran the following reaction in the laboratory at 311 K:CH4(g) + CCl4(g) 2CH2Cl2(g)When she introduced 4.10×10-2 moles o

statuscvo [17]

Answer: The value of $K_{eq}$ is 0.044

Explanation:

We are given:

Initial moles of methane = $4.10\times 10^{-2}mol=0.0410moles$

Initial moles of carbon tetrachloride = $6.51\times 10^{-2}mol=0.0651moles$

Volume of the container = 1.00 L

Concentration of a substance is calculated by:

$\text{Concentration}=\frac{\text{Number of moles}}{\text{Volume}}$

So, concentration of methane = $\frac{0.0410}{1.00}=0.0410M$

Concentration of carbon tetrachloride = $\frac{0.0651}{1.00}=0.0651M$

The given chemical equation follows:

$CH_4(g)+CCl_4(g)\rightleftharpoons 2CH_2Cl_2(g)$

Initial: 0.0410 0.0651

At eqllm: 0.0410-x 0.0651-x 2x

We are given:

Equilibrium concentration of carbon tetrachloride = $6.02\times 10^{-2}M=0.0602M$

Evaluating the value of 'x', we get:

$\Rightarrow (0.0651-x)=0.0602\\\\\Rightarrow x=0.0049M$

Now, equilibrium concentration of methane = $0.0410-x=[0.0410-0.0049]=0.0361M$

Equilibrium concentration of $CH_2Cl_2=2x=[2\times 0.0049]=0.0098M$

The expression of $K_{eq}$ for the above reaction follows:

$K_{eq}=\frac{[CH_2Cl_2]^2}{[CH_4]\times [CCl_4]}$

Putting values in above expression, we get:

$K_{eq}=\frac{(0.0098)^2}{0.0361\times 0.0603}\\\\K_{eq}=0.044$

Hence, the value of $K_{eq}$ is 0.044

8 0

3 years ago

(2) 8.1.3 Write down the structural formula of alcohol used in this reaction.

vitfil [10]

Answer:

-OH

Explanation:

Alcohols generally have the structural formula OH

for example, ethanols structural formula is C2H5OH

7 0

2 years ago

Determine the expected diffraction angle for the first-order diffraction from the (111) set of planes for FCC nickel (Ni) when m

faust18 [17]

Answer:

56°

Explanation:

First calculate $a:$

$a=2 R \sqrt{2}=2(0.1246) \sqrt{2}=0.352 \mathrm{nm}$

The interplanar spacing can be calculated from:

$d_{111}=\frac{a}{\sqrt{1^{2}+1^{2}+1^{2}}}=\frac{0.352}{\sqrt{3}}=0.203 \mathrm{nm}$

The diffraction angle is determined from:

$\sin \theta=\frac{n \lambda}{2 d_{111}}=\frac{1(0.1927)}{2(0.2035)}=0.476$

Solve for $\theta$

$\theta=\sin ^{-1}(0.476)=28^{\circ}$

The diffraction angle is:

$2 \theta=2\left(28^{\circ}\right)=56^{\circ}$

4 0

3 years ago

The H+ ion concentration of a solution is 1 x 10 ^ -5 M. This solution is...

pav-90 [236]

Answer:

To know this

get the pH

pH= -log(H+)

pH= -log(1x10^-5)

pH= 5.

It is Acidic.

Acidic ranges from 1 - 7

It falls within this range

3 0

3 years ago