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2 years ago

Which of the following is true about the concept of half-life?

Chemistry

2 answers:

Reptile [31]2 years ago

8 0

Its A. because it measures the rate of the decay of the isotope

Margaret [11]2 years ago

3 0

it is A Half-life measures the rate of decay of a radioisotope.

I took the test

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Equation Unbalanced : __AlCl3 + __F2 --> __AlF3 + __Cl2

Greeley [361]

$\\ \rm\Rrightarrow 2AlCl_3+3F_2\longrightarrow 2AlF_3+3Cl_2$

Balanced

3mols of fluorine produce 2 mol chlorine

1 mol fluorine produces 2/3=0.6mol chlorine

Moles of fluorine gas=

4/19
0.2mol.approx

Moles of chlorine:-

0.2(0.6)=0.18mol

Mass of chlorine

71(0.18)
12.78g

6 0

2 years ago

Consider the reaction Mg₂Si(s) + 4 H₂O(ℓ) → 2 Mg(OH)₂(aq) + SiH₄(g). How many grams of silane gas (SiH₄) are formed if 25.0 g of

Neko [114]

Answer:

10.60 grams of silane gas are formed.

Explanation:

From the reaction:

Mg₂Si(s) + 4H₂O(l) → 2Mg(OH)₂(aq) + SiH₄(g)

We know that the limiting reactant is Mg₂Si, so to find the mass of SiH₄ formed we need to calculate the number of moles of Mg₂Si:

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}}$

Where:

m: is the mass of Mg₂Si = 25.0 g

M: is the molar mass of Mg₂Si = 76.69 g/mol

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}} = \frac{25.0 g}{76.69 g/mol} = 0.33 moles$

Now, the stoichiometric relation between Mg₂Si and SiH₄ is 1:1 so:

$\eta_{Mg_{2}Si} = \eta_{SiH_{4}} = 0.33 moles$

Finally, the mass of SiH₄ is:

$m_{SiH_{4}} = \eta_{SiH_{4}}*M_{SiH_{4}} = 0.33 moles*32.12 g/mol = 10.60 g$

Therefore, 10.60 grams of silane gas are formed.

I hope it helps you!

3 0

2 years ago

This was in my chemistry class- <br> What's the color combination code?

Aleksandr-060686 [28]

Blue yellow purple green

3 0

2 years ago

Who invented carbon element?

igor_vitrenko [27]

Carbon discovered in Prehistoric times.. Discoverer will probably never be known

8 0

3 years ago

Elements and compounds are more similar to each other than they are to mixtures because:

Dovator [93]

Answer:

elements and compounds can only be liquids or solids, but mixtures can be solids, liquids or gases

Explanation:

Element: A substance that is made up of only one type of atom. Compound: A substance that is made up of more than one type of atom bonded together. Mixture: A combination of two or more elements or compounds which have not reacted to bond together; each part in the mixture retains its own properties.

7 0

2 years ago