Solids or liquids are not included in an equilibrium expression because:

How many atoms of cobalt are in one formula unit of cobalt (III) oxide? one two three six

IrinaK [193]

I believe the correct answer is the second option. There will be two cobalt atoms in one formula unit of cobalt (III) oxide. It has a chemical formula of Co2O3. This compound is does not naturally occur so it is being synthesized. It is mostly used as bleaching agent.

7 0

3 years ago

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How much energy is released by the decay of 3 grams of 230Th in the following reaction 230 Th - 226Ra + "He (230 Th = 229.9837 g

Serhud [2]

Answer: The energy released for the decay of 3 grams of 230-Thorium is $2.728\times 10^{-15}J$

Explanation:

First we have to calculate the mass defect $(\Delta m)$ .

The equation for the alpha decay of thorium nucleus follows:

$_{90}^{230}\textrm{Th}\rightarrow _{88}^{226}\textrm{Ra}+_2^{4}\textrm{He}$

To calculate the mass defect, we use the equation:

Mass defect = Sum of mass of product - Sum of mass of reactant

$\Delta m=(m_{Ra}+m_{He})-(m_{Th})$

$\Delta m=(225.9771+4.008)-(229.9837)=1.4\times 10^{-3}amu=2.324\times 10^{-30}kg$

(Conversion factor: $1amu=1.66\times 10^{-27}kg$ )

To calculate the energy released, we use Einstein equation, which is:

$E=\Delta mc^2$

$E=(2.324\times 10^{-30}kg)\times (3\times 10^8m/s)^2$

$E=2.0916\times 10^{-13}J$

The energy released for 230 grams of decay of thorium is $2.0916\times 10^{-13}J$

We need to calculate the energy released for the decay of 3 grams of thorium. By applying unitary method, we get:

As, 230 grams of Th release energy of = $2.0916\times 10^{-13}J$

Then, 3 grams of Th will release energy of = $\frac{2.0916\times 10^{-13}}{230}\times 3=2.728\times 10^{-15}J$

Hence, the energy released for the decay of 3 grams of 230-Thorium is $2.728\times 10^{-15}J$

5 0

3 years ago

Questioned document examiners prefer to work with copies of a questioned document in order to avoid damage to the original

gladu [14]

I think it is a False

4 0

2 years ago

Classify the chemical reaction shown here: CrF3+H3PO4→CrPO4+3HF

Lana71 [14]

The answer
he chemical reaction CrF3+H3PO4 → CrPO4 + 3HF
the main formula is
when we observe a reaction as follow:
XY + ZT --------------- XT + YZ
this is classified as double replacement reactions, this means: two ionic compounds exchange ions, producing 2 new ionic compounds.
in our case we have CrF3+H3PO4 → CrPO4 + 3HF
so the classification is double-replacement reactions

5 0

3 years ago

The fact that same molecules of matter have been around for years is supported by

Elza [17]

Answer:

The law of definite proportions

Explanation:

The law of definite proportions states that atoms combine in a molecule in a specific molar ratio or specific stoichiometry. For example, it's proved that regardless of the quantity we take, two hydrogen atoms always combine with one oxygen atom to form a water molecule.

Similarly, ionic substances follow the same pattern. Since the net charge of ionic salts should be equal to 0 and each element has a definite number of valence electrons in its shell all the time, the ions combine in a way, so that cations balance the charge of anions.

Essentially, the law of definite proportions is applicable and will be applicable in the future, since we know that each element has a fixed number of valence electrons in its ground state.

6 0

3 years ago