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3 years ago

Simple distillation is best used to separate two liquids that have boiling points that differ by

1 answer:

6 0

The boiling points need to differ by 50 degrees to enable their complete separation ie of two different liquids. The separation occurs by first evaporation of one of the liquids and then its condensation and collection. It is a physical process not a chemical one.

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(Please help will mark brainliest!)

arsen [322]

We know that Weighted atomic mass of Element is Calculated based upon their existence of isotopes and the Relative abundance of these isotopes.

Given that the Element X is Composed of :

Isotope Relative abundance Atomic Mass

⁵⁵X 70% 55

⁵⁶X 20% 56

⁵⁷X 10% 57

Weighted Atomic Mass of Element X :

= (0.70)(55) + (0.20)(56) + (0.10)(57)

= 38.50 + 11.2 + 5.70

= 55.4

So, the Weighted Atomic Mass of Element X is 55.4

6 0

3 years ago

The heat of fusion for water is 80. cal/g. How many calories of heat are needed to melt a 35 g ice cube that has a temperature o

HACTEHA [7]

Answer: 2800 calories

Explanation:

Latent heat of fusion is the amount of heat required to convert 1 mole of solid to liquid at atmospheric pressure.

Amount of heat required to fuse 1 gram of water = 80 cal

Mass of ice given = 35 gram

Heat required to fuse 1 g of ice at $0^0C$ = 80 cal

Thus Heat required to fuse 35 g of ice = $\frac{80}{1}\times 35=2800cal$

Thus 2800 calories of energy is required to melt 35 g ice cube

6 0

4 years ago

Silver occurs in trace amounts in some ores of lead, and lead can displace silver from solution: Pb(s) + 2Ag+ (aq) LaTeX: \longr

VikaD [51]

Answer : The value of $\Delta G^o$ and K is, -180 kJ/mol and $3.6\times 10^{31}$

Explanation :

The balanced cell reaction will be,

$Pb(s)+2Ag^+(aq)\rightarrow Pb^{2+}(aq)+2Ag(g)$

The half-cell reactions are:

Oxidation reaction (anode) : $Pb(s)\rightarrow Pb^{2+}(aq)+2e^-$

Reduction reaction (cathode) : $2Ag^+(aq)+2e^-\rightarrow 2Ag(g)$

Relationship between standard Gibbs free energy and standard electrode potential follows:

$\Delta G^o=-nFE^o_{cell}$

where,

$\Delta G^o$ = standard Gibbs free energy

F = Faraday constant = 96500 C

n = number of electrons in oxidation-reduction reaction = 2

$E^o_{cell}$ = standard electrode potential of the cell = 0.93 V

Now put all the given values in the above formula, we get:

$\Delta G^o=-2\times 96500\times 0.93$

$\Delta G^o=-179490J/mol=-179.49kJ/mol\approx -180kJ/mol$

Now we have to calculate the value of 'K'.

$\Delta G^o=-RT\ln K$

where,

$\Delta G_^o$ = standard Gibbs free energy = -180 kJ/mol

R = gas constant = $8.314\times 10^{-3}kJ/mole.K$

T = temperature = 298 K

K = equilibrium constant = ?

Now put all the given values in the above formula 1, we get:

$-180kJ/mol=-(8.314\times 10^{-3}kJ/mole.K)\times (298K)\times \ln K$

$K=3.6\times 10^{31}$

Therefore, the value of $\Delta G^o$ and K is, -180 kJ/mol and $3.6\times 10^{31}$

5 0

3 years ago

If the oxidation number of an atom decreases, the atom has undergone oxidation.

Bumek [7]

Oxidation is a process when an atom, a group of atoms, or an ion loses electrons.

For example,

Cu⁰ -------> Cu⁺² + 2e⁻. This is an oxidation process.

As we can see an oxidation number was 0, and it became +2. The oxidation number is increased. Oxidation number of the atom, when an atom has undergone oxidation, increases.

So, answer is b.False.

8 0

3 years ago

An automated filling machine is used to fill bottles with liquid detergent. A random sample of 20 bottles results in a sample va

taurus [48]

Answer:

No, there is no evidence that the manufacturer has a problem with underfilled or overfilled bottles, due that according our results we cannot reject the null hypothesis.

Explanation:

according to this exercise we have the following:

σ^2 =< 0.01 (null hypothesis)

σ^2 > 0.01 (alternative hypothesis)

To solve we can use the chi-square statistical test. To reject or not the hypothesis, we have that the rejection region X^2 > 30.14

Thus:

X^2 = ((n-1) * s^2)/σ^2 = ((20-1)*0.0153)/0.01 = 29.1

Since 29.1 < 30.14, we cannot reject the null hypothesis.

4 0

3 years ago

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