A cube made of an unknown material has a height of 9 cm. The mass of this cube is 3,645 grams.

You have a gas stored in a rigid container (fixed volume). Explain the relationship between a decrease in temperature, collision

alexandr1967 [171]

Answer:

A decrease in temperature would decrease kinetic energy, therefore decreasing collisions possible.

Explanation:

A gas at a fixed volume is going to have collisions automatically. If you decrease the temperature (same thing as decreasing kinetic energy) you are cooling down the molecules in the container which gives them less energy and "relaxes" them. This decrease in energy causes them to move around much slower and causing less collisions, at a much slower rate. In a perfect world, these collisions do not slow down the molecule but we know that they do, just a very very small unmeasurable amount.

6 0

3 years ago

Which of the following is not an example of a chemical change?

elena55 [62]

This would be C. A car rusting

5 0

3 years ago

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Is a burning log an exothermic or endothermic event if the log is the system?

denpristay [2]

It would be endothermic because the log is in the system.

6 0

2 years ago

What is the hydronium ion concentration of a 0.100 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociatio

evablogger [386]

Answer:

1.3×10⁻³ M

Explanation:

Hello,

In this case, given the dissociation reaction of acetic acid:

$CH_3CO_2H(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + CH_3CO_2^-(aq)$

We can write the law of mass action for it:

$Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}$

Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change $x$ due to the dissociation extent, we are able to rewrite it as shown below:

$1.8x10^{-5}=\frac{x*x}{0.100-x}$

Thus, via the quadratic equation or solve, we obtain the following solutions:

$x_1=-0.00135M\\x_2=0.00133M$

Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.

Regards.

8 0

3 years ago

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How many grams of phosphorus are in a sample of Ca3(PO4)2 that contains 50.0 g of calcium? Answer: ________ grams of phosphorus.

wel

<u>Answer:</u> The mass of phosphorus that is present for given amount of calcium is 28.53 g.

<u>Explanation:</u>

We are given:

Mass of calcium = 50 grams

The chemical formula of calcium phosphate is $Ca_3(PO_4)_2$

Molar mass of calcium = 40 g/mol

Molar mass of phosphorus = 31 g/mol

In 1 mole of calcium phosphate, 120 grams of calcium is combining with 62 grams of phosphorus.

So, 50 grams of calcium will combine with = $\frac{62}{120}\times 50=28.53g$ of phosphorus.

Hence, the mass of phosphorus that is present for given amount of calcium is 28.53 g.

6 0

2 years ago