The testable question which will provide evidence that elements in the same group have similar properties is valency
<h3>What is the valency?</h3>
In essence, how many electrons are present in their outermost shell.
Valency and Groups in the periodic table, elements are arranged in order of their atomic numbers and hence, the periodic table is a systematic arrangement of elements in an array of vertical columns called Groups and horizontal arrays called Periods.
which of the following testable questions will provide evidence that elements in the same group have similar properties A. Valency B. Orbit C. Group D. Period
Since, the reactive capacities of elements is dependent on the number of electrons on its outermost shell, we can conclude on this note that, Elements in the same group have similar properties.
Learn more on Groups and Valency:
brainly.com/question/1645905
Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of
= 183.511 g/mole
- First we have to calculate the moles of Cu.

The moles of Cu = 4.7209 moles
From the given chemical formula,
we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of
= 4.4209 moles
- Now we have to calculate the mass of
.
Mass of
= Moles of
× Molar mass of
= 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of
= 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Answer:
E = 0.062 V
Explanation:
(a) See the attached file for the answer
(b)
Calculating the voltage (E) using the formula;
E = - (2.303RT/nf)log Cathode/Anode
Where,
R = 8.314 J/K/mol
T = 35°C = 308 K
F- Faraday's constant = 96500 C/mol,
n = number of moles of electron = 2
Substituting, we have
E = -(2.303 * 8.314 *308/2*96500) *log (0.03/3)
= -0.031 * -2
= 0.062V
Therefore, the voltmeter will show a voltage of 0.062 V
Answer: Option (B) is the correct answer.
Explanation:
Degree of randomness of the molecules of a substance is known as entropy. More is the kinetic energy between the molecules of a substance more will be the degree of randomness.
Therefore, when a substance is present in a gaseous state then it has the maximum entropy. In liquid state, molecules are closer to each other so, there is less randomness between them.
On the other hand, in solid state molecules are much more closer to each other as they arr held by strong intermolecular forces of attraction. Therefore, they have very less entropy.
- When liquid water is formed from gaseous hydrogen and oxygen molecules then gas is changing into liquid. So, there is decrease in entropy.
- When
decomposes then the reaction will be as follows.
Since, 1 mole is producing 2 moles. This means that degree of randomness is increasing as both the molecules are present in gaseous form.
- In formation of a precipitate, aqueous solution is changing into solid state. Hence, degree of randomness is decreasing.
- Rusting of iron also leads to the formation of solid as it forms
.
Thus, we can conclude that decomposition of
gas to
gas is the process that is expected to have an increase in entropy.
Answer: The answer is B
Explanation:
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