Gas a (L^2. atm/mol^2) b(L/mol)

zalisa [80]

$174 \; \text{protons} / (29 \; \text{copper atoms} \cdot \text{proton}^{-1}) = 6 \; \text{copper atoms}$

Thus 174 protons would make at most 6 copper atoms. However, it would take 174 extra electrons (29 per atom) and even more neutrons than that to construct neutral copper atoms with stable nuclei.

7 0

3 years ago

Compared to ionic compounds, molecular compounds generally have

Stella [2.4K]

B. poor conductivity

3 0

3 years ago

Which of the following is an oxidation-reduction reaction? a. HCl(aq) + LiOH(aq) → LiCl(aq) + H2O(l) b. Pb(C2H3O2)2(aq) + 2 NaCl

saw5 [17]

Answer: Option (d) is the correct answer.

Explanation:

A reaction in which there occurs change in oxidation state of reacting species is known as an oxidation-reduction reaction.

(a) $HCl(aq) + LiOH(aq) \rightarrow LiCl(aq) + H_{2}O(l)$

Will be written as:

$H^{+} + Cl^{-} + Li^{+} + OH^{-} \rightarrow Li^{+} + Cl^{-} + H^{+} + OH^{-}$

In this reaction, there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.

(b) $Pb(C_{2}H_{3}O_{2})_{2}(aq) + 2NaCl(aq) \rightarrow PbCl_{2}(s) + 2 NaC_{2}H_{3}O_{2}(aq)$

Will be written as:

$Pb^{2+} + 2C_{2}H_{3}OO^{-} + 2Na^{+} + 2Cl^{-} \rightarrow Pb^{2+} + 2Cl^{-} + 2Na^{+} + 2C2H3OO^{-}$

Similarly here, there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.

(c) $NaI(aq) + AgNO_{3}(aq) \rightarrow AgI(s) + NaNO_{3}(aq)$

Will be written as:

$Na^{+} + I^{-} + Ag^{2+} + NO^{2-}_{3} \rightarrow AgI(s) + Na^{+} + NO^{2-}_{3}(aq)$

Here, also there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.

(d) $Mg(s) + 2 HCl(aq) \rightarrow MgCl_{2}(aq) + H_{2}(g)$

So, here there occurs change in oxidation state of Mg from 0 to +2 and oxidation state of H changes from +1 to 0. Hence, it is an oxidation-reduction reaction.

Thus, we can conclude that $Mg(s) + 2 HCl(aq) \rightarrow MgCl_{2}(aq) + H_{2}(g)$ is an oxidation-reduction reaction.

7 0

3 years ago

Which two body systems work together to deliver oxygen to cells? A. the digestive and respiratory systems B. the respiratory and

Ann [662]

The correct answer is option B, that is, the respiratory and circulatory systems.

The respiratory and circulatory system functions together to circulate oxygen and blood all through the body. The movement of air takes place in and out of the lungs via the bronchi, trachea, and bronchioles. The movement of blood takes place in and out of the lungs via the pulmonary veins and arteries, which associate with the heart.

The pulmonary arteries mediate deoxygenated blood to the lungs from the heart, and the pulmonary veins carry oxygenated blood to the heart again so that it can be distributed to the rest of the body.

5 0

3 years ago

In a five-fold serial dilution of a 20 ug/mL solution, all tube dilutions are 1/5. What is the substance concentration in the th

sergij07 [2.7K]

Answer:

In the third tube, the concentration is 0.16 ug/mL

Explanation:

In the first step, the solution is diluted by 5. Then, the concentration will be

20 ug/mL / 5 = 4 ug/mL

Then, in the second step this 4 ug / ml solution is diluted by a factor of five again:

4 ug /ml / 5 = 0.8 ug/mL

This solution is then diluted again by 5 and the concentration in the third tube will be then:

0.8 ug/mL / 5 = <u>0.16 ug/mL </u>

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Another way to calculate this is to divide the original concentration by the dilution factor ( 5 in this case) elevated to the number of dilutions. In this case:

Concentration in the third tube = 20 ug/mL / 5³ = 0.16 ug/mL

3 0

3 years ago