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3 years ago

What are five ways people can study and explore space without phisically going there

Chemistry

1 answer:

son4ous [18]3 years ago

3 0

<span>I think we can use rovers, landers, orbiters, probes and satellites.

Hoped this helped</span>

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5. Which of the following statements is incorrect?

Vikki [24]

Answer:

c- dry cells can not be recharged

6 0

3 years ago

Given these reactions, where X represents a generic metal or metalloid 1 ) H 2 ( g ) + 1 2 O 2 ( g ) ⟶ H 2 O ( g ) Δ H 1 = − 241

anygoal [31]

Answer : The enthalpy of the given reaction will be, -1048.6 kJ

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

The main reaction is:

$XCl_4(s)+2H_2O(l)\rightarrow XO_2(s)+4HCl(g)$ $\Delta H=?$

The intermediate balanced chemical reactions are:

(1) $H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(g)$ $\Delta H_1=-241.8kJ$

(2) $X(s)+2Cl_2(g)\rightarrow XCl_4(s)$ $\Delta H_2=+461.9kJ$

(3) $\frac{1}{2}H_2(g)+\frac{1}{2}Cl_2(g)\rightarrow HCl(g)$ $\Delta H_3=-92.3kJ$

(4) $X(s)+O_2(g)\rightarrow XO_2(s)$ $\Delta H_4=-789.1kJ$

(5) $H_2O(g)\rightarrow H_2O(l)$ $\Delta H_5=-44.0kJ$

Now reversing reaction 2, multiplying reaction 3 by 4, reversing reaction 1 and multiplying by 2, reversing reaction 5 and multiplying by 2 and then adding all the equations, we get :

(1) $2H_2O(g)\rightarrow 2H_2(g)+O_2(g)$ $\Delta H_1=2\times 241.8kJ=483.6kJ$

(2) $XCl_4(s)\rightarrow X(s)+2Cl_2(g)$ $\Delta H_2=-461.9kJ$

(3) $2H_2(g)+2Cl_2(g)\rightarrow 4HCl(g)$ $\Delta H_3=4\times -92.3kJ=-369.2kJ$

(4) $X(s)+O_2(g)\rightarrow XO_2(s)$ $\Delta H_4=-789.1kJ$

(5) $2H_2O(l)\rightarrow 2H_2O(g)$ $\Delta H_5=2\times 44.0kJ=88.0kJ$

The expression for enthalpy of main reaction will be:

$\Delta H=\Delta H_1+\Delta H_2+\Delta H_3+\Delta H_4+\Delta H_5$

$\Delta H=(483.6)+(-461.9)+(-369.2)+(-789.1)+(88.0)$

$\Delta H=-1048.6kJ$

Therefore, the enthalpy of the given reaction will be, -1048.6 kJ

4 0

3 years ago

Which of the following does NOT involve a change of state? a. pouring water into a vacuum-insulated bottle b. sublimation of dry

Elena L [17]

<h2> The correct option is (a).</h2>

Explanation:

There is no change of state in pouring water into a vacuum insulated bottle as the vacuum created inside the bottle only reduces the time limit for the transfer of heat by conduction and convection.
It helps the content filled in the bottle to be hot and cool for a longer time.

Hence, option (a) is correct.

Rest of the options (b), (c), (d), (e) is not correct because of the following reasons:

In the sublimation of dry ice, the dry ice (solid-state) is changed to the vapour form.
In the freezing of water, the liquid state is changed to solid-state.
During the vaporization of alcohol, the liquid state is changed to the vapour form.
During the melting of ice, the solid-state is changed to the liquid state.

6 0

4 years ago

If a shell can hold a maximum of 32 electrons, what is the value of n

just olya [345]

I think the answe would be 16n

5 0

3 years ago

Help?… thank you very much! 100 points

Marianna [84]

Answer:

Option B is correct.

Explanation:

They live in less extreme environment than most archaebacteria.

Hoped this helped.

7 0

2 years ago