Can someone answer these two questions? thanks

What is a bond between a positive and a negative ion charge?

klasskru [66]

Answer:

Ionic Bond

Explanation:

5 0

3 years ago

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A mole of ideal gas expands at T=27 °C. The pressure changes from 20 atm to 1 atm. What’s the work that the gas has done and wha

Airida [17]

Answer:

The work made by the gas is 7475.69 joules
The heat absorbed is 7475.69 joules

Explanation:

We know that the differential work made by the gas its defined as:

$dW = P \ dv$

We can solve this by integration:

$\Delta W = \int\limits_{s_1}^{s_2}\,dW = \int\limits_{v_1}^{v_2} P \ dv$

but, first, we need to find the dependence of Pressure with Volume. For this, we can use the ideal gas law

$P \ V = \ n \ R \ T$

$P = \frac{\ n \ R \ T}{V}$

This give us

$\int\limits_{v_1}^{v_2} P \ dv = \int\limits_{v_1}^{v_2} \frac{\ n \ R \ T}{V} \ dv$

As n, R and T are constants

$\int\limits_{v_1}^{v_2} P \ dv = \ n \ R \ T \int\limits_{v_1}^{v_2} \frac{1}{V} \ dv$

$\Delta W= \ n \ R \ T \left [ ln (V) \right ]^{v_2}_{v_1}$

$\Delta W = \ n \ R \ T ( ln (v_2) - ln (v_1 )$

$\Delta W = \ n \ R \ T ln (\frac{v_2}{v_1})$

But the volume is:

$V = \frac{\ n \ R \ T}{P}$

$\Delta W = \ n \ R \ T ln(\frac{\frac{\ n \ R \ T}{P_2}}{\frac{\ n \ R \ T}{P_1}} )$

$\Delta W = \ n \ R \ T ln(\frac{P_1}{P_2})$

Now, lets use the value from the problem.

The temperature its:

$T = 27 \° C = 300.15 \ K$

The ideal gas constant:

$R = 8.314 \frac{m^3 \ Pa}{K \ mol}$

So:

$\Delta W = \ 1 mol \ 8.314 \frac{m^3 \ Pa}{K \ mol} \ 300.15 \ K ln (\frac{20 atm}{1 atm})$

$\Delta W = 7475.69 joules$

We know that, for an ideal gas, the energy is:

$E= c_v n R T$

where $c_v$ its the internal energy of the gas. As the temperature its constant, we know that the gas must have the energy is constant.

By the first law of thermodynamics, we know

$\Delta E = \Delta Q - \Delta W$

where $\Delta W$ is the Work made by the gas (please, be careful with this sign convention, its not always the same.)

So:

$\Delta E = 0$

$\Delta Q = \Delta W$

7 0

2 years ago

The 88-lb force P is applied to the 210-lb crate, which is stationary before the force is applied. Determine the magnitude and d

Marina86 [1]

Answer:

$F=-88Ib$

Explanation:

From the question we are told that:

Force P=88Ib

Mass of crate M_c=210Ib

Generally the equation for Frictional force F is mathematically given by

$Friction\ force (f) = friction\ coefficient\ (u) * Normal\ reaction (N)$

$F=u*N$

with $\mu =0.47$

$F=98.7Ib$

Therefore since Static Friction supersedes applied force body remains at rest.

Frictional force =88Ib (negative)

$F=-88Ib$

5 0

2 years ago

Why mirrors show texts in reverse order?

bogdanovich [222]

Mirrors reflect meaning shows what would be seen if everything was turned around, therefore, it shows text backwards because if it is turned around, it is in reverse order.

7 0

2 years ago

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When and where did the first nuclear reactor generate electricity

masha68 [24]

<h2>Answer: On December 20th, 1951 in Idaho, United States. </h2>

The world's first experimental nuclear power plant was the Experimental Breeder Reactor Number One (EBR-I), which was built in a desert in Idaho, United States.

This reactor made history when, on December 20th, 1951, four 200-watt light bulbs were illuminated by means of atomic energy, specifically by nuclear fission reaction.

5 0

3 years ago