6.02 x 10 atoms of cu

To separate a mixture of hard candies and marbles, the most efficient method would be

frozen [14]

I think hand picking is best for this case.another method can be done in which first u have melt those candies with marbles.u will hart candy will melt quickly.so,when candies melt ,u will find marbles are still solid but candies are in liquid form .now take a net and purify that solution(candies and marbles).now the candies will pass through net but marbles will stuck in upper net.remove marbles now

6 0

4 years ago

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For which of the processes below will δs be a positive number? 1) ch4(g) → ch4(l) 2) n2h4(g) → n2(g) + 2h2(g) 3) h2o(s) → h2o(g)

Shalnov [3]

The entropy of the gaseous substance is more in comparison to the liquid or solid form of the same substance at same temperature and pressure conditions.

More is the number of particles more will be the entropy of the system.

In the first chemical reaction, CH₄ (g) → CH₄ (l)

Since, the reactants are in gaseous phase and the products are in liquid phase, the entropy is decreasing during the reaction.

In the second chemical reaction,

N₂H₄ (g) → N₂ (g) + 2H₂ (g)

Since, one mole of the reactant in gaseous phase is decomposing to produce three moles of product in gaseous phase, the entropy is increasing during the reaction.

In the third chemical reaction, H₂O (s) → H₂O (g)

Since, the reactant is in solid phase and product are in gaseous phase. The entropy is increasing during the reaction.

Thus, the entropy is increasing in the 2nd and 3rd reactions.

3 0

3 years ago

A car travels 75 mi/hr. How many hours will it take to travel 837 km? (Pick the answer closest to the correct answer,

nlexa [21]

Answer:

6.9 hours

Explanation:

In order to solve this problem we'll convert 837 km to miles (another option would be to convert 75 mi/hr to km/hr). To make said conversion we'll use the given conversion factor:

837 km * $\frac{1mi}{1.61km}$ = 519.88 mi

Finally we calculate the time required to travel said distance at a constant speed of 75 mi/hr:

519.88 mi ÷ 75 mi/hr = 6.9 hr

5 0

3 years ago

Apply the given electronegativities to each bond in the examples below to see which are polar and which are nonpolar. Multiple b

Nesterboy [21]

Answer:

H-O-H polar

O-C-O nonpolar

H-C-N polar

Explanation:

Looking up the electronegativities of the atoms involved in this question, we have:

Atom Electronegativity

H 2.2

C 2.55

N 3.04

O 3.44

All of the atoms differ in electronegativity resulting in individual dipole moments in H-O, O-C, H-C and C-N bonds. To find if the molecules will be polar we need to consider the structure of the compound to see if there is a resultant dipole moment.

In H-O-H, we have 2 lone pairs of electrons around the central oxygen atom which push the angle H-O-H of the ideal tetrahedral structure to be smaller than 109.5 º resulting in an overall dipole moment making it polar.

In O-C-O, we have two dipole moments that exactly cancel each other in the linear molecule since the central carbon atom does not have lone pairs of electrons since it has 2 double bonds. Therefore the molecule is nonpolar.

In H-C-N, again we have have a central carbon atom without lone pairs of electrons and the shape of the molecule is linear. But, now we have that the dipole moment in C-N is stronger than the H-C dipole because of the difference in electronegativity of nitrogen compared to hydrogen. The molecule has an overall dipole moment and it is polar.

8 0

3 years ago

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The water in a 150-mL flask is poured into a beaker that contains 600 mL of ethyl alcohol. Which substance is the solvent in thi

Degger [83]

I'm pretty sure it's "water because it is a very polar compound" since I know ethyl alcohol DOES dissolve in water and by using this knowledge I just used the process of elimination.

I know that doesn't help very much though, good luck.

8 0

3 years ago

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