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3 years ago

Give the number of significant figures in this number: 7.8 x 10¹²

2 answers:

7 0

Two! 7 and 8! If you put a number in scientific notation like that, everything before the multiplication sign is significant

wlad13 [49]3 years ago

5 0

The answer would be:

Two significant figures

In scientific notation, the only significant numbers would be in the coefficient. In your case:

7.8 x 10¹²

7.8 is the coefficient and there are two numbers, 7 and 8. This means that they are the only significant numbers.

But take note:

ALL NUMBERS IN THE COEFFICIENT ARE SIGNIFICANT!

So if you write something like:

7.80 x 10¹² (which is technically the same as the first)

There would be 3 significant figures, (7, 8 and zero)

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pochemuha

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Explanation:

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2 years ago

What would cause the shape of a molecule to be tetrahedral?

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3 years ago

Which of the following is not an example of prediction?

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Hypothesis: Sunlight is necessary for seedling growth.

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3 years ago

Consider this equilibrium: N2(g) + 3H2(g) 2NH3(g) + energy. Certain conditions provide less than 10% yield of NH3 at equilibrium

alisha [4.7K]

The correct option is this: THE KEQ IS SMALL AND THE REACTANT ARE FAVOURED.
Since we are told in the question that the reaction give rise to only 10% product, this means that much product are not been produced, thus the reactants are favoured. Keq stands for the equilibrium constant of the reaction and it measures the rate at which the reactants are converted to products. For this reaction, the equilibrium constant is small and the backward reaction [reactant] is favoured.

5 0

3 years ago

Use the van der Waals equation and the ideal gas equation to calculate the volume of 1.000 mol of neon at a pressure of 500.0 at

lara31 [8.8K]

Answer:

$v^{VdW}=0.0704\frac{L}{mol}$

$v^{ideal}=0.05816\frac{L}{mol}$

Differences:

- The gas is at a very high pressure, which causes strong nonidealities.

- Attraction and repulsion actually phenomena exist among molecules, which is not considered by the ideal gas equation.

Explanation:

Hello,

In this case, the VdW equation takes the typical form:

$p=\frac{RT}{v-b}-\frac{a}{v^2}$

Whereas $a$ and $b$ are referred to the attraction and repulsion effect, in such a way, for neon, such values are 0.208 bar*L²/mol² and 0.01672 L/mol respectively. However, with the given information, the polynomic form of the VdW equation is:

$v^3-(\frac{RT}{P}+b)v^2+\frac{a}{p} v-\frac{ab}{p} =0$

Which in terms of the molar volume becomes:

$v^3-(\frac{0.083\frac{bar*L}{mol*K}*355.0K}{506.625bar}+0.01672\frac{L}{mol} )v^2+(\frac{0.208\frac{bar*L^2}{mol^2} }{506.625bar})v-\frac{0.208\frac{bar*L^2}{mol^2}*0.01672\frac{L}{mol}}{506.625bar} =0$