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3 years ago

How many moles are present in a 24.5 gram sample of K2Cr2O7?

Chemistry

1 answer:

attashe74 [19]3 years ago

6 0

The answer to this is solved through stochiometry: the answer is this: 0.0833mol

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What is the charge of hydroxide?

katen-ka-za [31]

Answer: 1- charge

We see that hydroxide has a 1- charge, which means the ion has one more electron than there are protons in the nuclei of a hydrogen atom plus an oxygen atom.

Explanation:

6 0

3 years ago

A possible mechanism for the overall reaction represented above is the following.

Phantasy [73]

Answer:

Explanation:

The slow step of the reaction is the rate determining step. This means to get the rate law for a chemical activity with slow and fast steps, we have to consider the slow step if we are to write the rate law successfully.

Since the compound NO is reacting with itself, we have to raise the value of the concentration in the square bracket by 2. That is why we have the concentration squared.

4 0

3 years ago

What are 3-5 uses for solar energy

raketka [301]

Answer:As heat for making hot water, heating buildings and cooking.

To generate electricity with solar cells or heat engines.

To take the salt away from sea water.

To use sun rays for drying clothes and towels.

It is used by plants for the process of photosynthesis.

Explanation:

3 0

3 years ago

For the gas phase decomposition of phosphine at 120 °C, the rate of the reaction is determined by measuring the appearance of H2

Dmitry_Shevchenko [17]

Answer:

Rate = 1.09*10^-3 (mol H2/L)/s

Explanation:

Given:

Initial concentration of H2, C1 = 0 M

Final concentration of H2, C2 = 0.101 M

Time taken, t = 93.0 s

To determine:

The rate of the given reaction

Calculation:

The decomposition of PH3 is represented by the following chemical reaction

$4 PH3(g)\rightarrow P4(g) + 6 H2(g)$

Reaction rate in terms of the appearance of H2 is given as:

$Rate = +\frac{1}{6}*\frac{\Delta [H2]]}{\Delta t}$

$Rate = +\frac{1}{6}*\frac{C2[H2]-C1[H2]}{\Delta t}$

Here C1(H2) = 0 M and C2(H2) = 0.101 M

Δt = 93.0 s

$Rate = \frac{(0.101-0.0)M}{93.0 s} =1.09*10^{-3} M/s$

Since molarity M = mole/L

rate = 1.09*10^-3 (mol H2/L)/s

7 0

3 years ago

Barium is a very reactive metal in the presence of oxygen and water, thus its density cannot be measured by water displacement.

Setler79 [48]

Answer:

The correct answer is 4.502 g per ml.

Explanation:

Based on the given question, the sum of the mass of mesitylene and barium together is 148.792 grams. The mass of barium given is 77.240 grams. Therefore, the mass of mesitylene will be,

Mass of mesitylene = Total mass - Mass of barium

= 148.792 - 77.240

= 71.552 grams

The density of mesitylene is 0.86370 g per ml. To calculate the volume of mesitylene, the formula to be used is,

Volume = mass / density. Now, putting the values we get,

Volume = 71.552 / 0.86370 = 82.8436 ml.

As the total volume is 100 ml, therefore, the volume of Ba will be,

Volume of Ba = 100-82.8436 = 17.1564 ml

The density of Ba at 20 degree C can be calculated by using the formula,

Density = mass / volume. Now putting the values we get,

Density = 77.240 g / 17.1564 ml

= 4.502 g per ml

8 0

3 years ago