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3 years ago

How is enthalpy used to predict whether a reaction is endothermic or exothermic?

1 answer:

4 0

The value of enthalpy of a reaction can be a useful tool in determining the type of reaction it is. If the enthalpy is negative the reaction is exothermic and if the enthalpy is positive the reaction is endothermic. Hope this answers the question. Have a nice day.

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Oxidation state of Nitrogen in N2O5

balandron [24]

Explanation:

Oxidation state of Nitrogen in N2O5 is +5

7 0

2 years ago

Draw the isotopic notation for an element with 15 protons, 18 neutrons and 18 electrons

tatiyna

Answer:

can't be done

Explanation:

protons and electrons always are the same number,and the neutrons are found by subtracting the atomic mass and protons/electrons soooooooo it can't have 15 protons, 18 electrons, and 18 neutrons.......i hope this helped if not please tell me.

5 0

3 years ago

How does air above a heated surface move?

anzhelika [568]

When air is warmed up, its molecules move faster and faster and as a result they move further from each other. They still have the same mass, but they now occupy a larger volume. This means that its density is smaller.
The opposite when air is cooled off. The molecules slow down, get closer together, occupy a smaller volume and therefore its density is bigger.

When air is warmed up, it goes up. Once it's up there, is cools off and goes back down. Near the heated surface the air gets warmed up again, goes up, cools down, goes back down, and again and again.
that is called convection cells

6 0

3 years ago

4) What volume will the gas in the balloon at right occupy at 250k? balloon: 4.3L 350K

swat32

Answer:

2.87 liter.

Explanation:

Given:

Initially volume of balloon = 4.3 liter

Initially temperature of balloon = 350 K

Question asked:

What volume will the gas in the balloon occupy at 250 K ?

Solution:

By using:

$Pv =nRT$

Assuming pressure as constant,

V∝ T

Now, let K is the constant.

V = KT

Let initial volume of balloon , $V_{1}$ = 4.3 liter

1000 liter = 1 meter cube

1 liter = $\frac{1}{1000} m^{3} = 10^{-3} m^{3$

4.3 liter = $4.3\times10^{-3}=4.3\times10^{-3} m^{3}$

And initial temperature of balloon, $T_{1}$ = 350 K

Let the final volume of balloon is $V_{2}$

And as given, final temperature of balloon, $T_{2}$ is 250 K

Now, $V_{1} = KT_{1}$

$4.3\times10^{-3}=K\times350\ (equation\ 1 )$

$V_{2} = KT_{2}$

$=K\times250\ (equation 2)$

Dividing equation 1 and 2,

$\frac{4.3\times10^{-3}}{V_{2} } =\frac{K\times350}{K\times250}$

K cancelled by K.

By cross multiplication:

$350V_{2} =4.3\times10^{-3} \times250\\V_{2} =\frac{ 4.3\times10^{-3} \times250\\}{350} \\ = \frac{1075\times10^{-3}}{350} \\ =2.87\times10^{-3}m^{3}$

Now, convert it into liter with the help of calculation done above,

$2.87\times10^{-3} \times1000\\2.87\times10^{-3} \times10^{3} \\2.87\ liter$

Therefore, volume of the gas in the balloon at 250 K will be 2.87 liter.

4 0

3 years ago

Please hep its my last question

atroni [7]

Answer:Noble gases:

are highly reactive.

react only with other gases.

do not appear in the periodic table.

are not very reactive with other elements.

Explanation:Noble gases:

are highly reactive.

react only with other gases.

do not appear in the periodic table.

are not very reactive with other elements.

7 0

2 years ago