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2 years ago

Which of the following is not a trend that varies systematically in the periodic table

Chemistry

2 answers:

UNO [17]2 years ago

5 0

Answer:

B: Symbols of Elements

Explanation:

juin [17]2 years ago

3 0

Answer: B: Symbols of Elements

Explanation:

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How many moles in 5 grams of gold

Ainat [17]

There is 0.02538502095915 Moles in 5 grams of gold.

8 0

3 years ago

Read 2 more answers

Which of the following produces a chemical change?

Svetlanka [38]

Exposure to chemicals.

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3 years ago

The second order reaction A → Products takes 13.5 s for the concentration of A to decrease from 0.740 M to 0.319 M. What is the

Ivanshal [37]

The rate constant of the second order reaction is 0.137 M-1s-1.

<h3>What is the rate constant?</h3>

For the second order reaction we can write;

1/[A] = kt + 1/[A]o

[A]o = initial concentration

[A] = final concentration

k = rate constant

t = time

Now;

1/0.319 = 13.5k + 1/ 0.740

1/0.319 - 1/0.740 = 13.5k

3.13 - 1.35 = 13k

k = 3.13 - 1.35/13

k = 0.137 M-1s-1

Learn more about second order reaction:brainly.com/question/12446045

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2 years ago

Calcium nitrate and ammonium fluoride react to form calcium fluoride, dinitrogen monoxide, and water vapor. How many grams of di

pychu [463]

Answer:

16.79 grams of dinitrogen monoxide are present after 31.3 g of calcium nitrate and 38.7 g of ammonium fluoride react completely. And calcium nitrate is a limiting reactant. Explanation:

$Ca(NO_3)_2(aq)+2NH_4F(aq)\rightarrow CaF_2(aq)+2N_2O(g)+4H_2O(g)$

Moles of calcium nitrate = $\frac{31.3 g}{164 g/mol}=0.1908 mol$

Moles of ammonium fluoride = $\frac{38.7 g}{37 g/mol}=1.046 mol$

According to reaction , 2 moles of ammonium fluoride reacts with 1 mole of calcium nitrate.

Then 1.046 moles of ammonium fluoride will react with :

$\frac{1}{2}\times 1.046 mol=0.523 mol$ calcium nitarte .

This means that ammonium fluoride is in excess amount and calcium nitrate is in limiting amount.

Hence, calcium nitrate is a limiting reactant.

So, amount of dinitrogen monoxide will depend upon moles of calcium nitrate.

So, according to reaction , 1 mole of calcium nitarte gives 2 moles of dinitrogen monoxide gas .

Then 0.1908 moles of calcium nitrate will give:

$\frac{2}{1}\times 0.1908 mol=0.3816 mol$ of dinitrogen monoxide gas.

Mass of 0.03816 moles of dinitrogen monoxide gas:

0.03816 mol × 44 g/mol = 16.79 g

16.79 grams of dinitrogen monoxide are present after 31.3 g of calcium nitrate and 38.7 g of ammonium fluoride react completely. And calcium nitrate is a limiting reactant.

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3 years ago

One of the postulates of bohr's atomic model of a moving electron is that angular momentum of a moving electron is quantized. Ex

oksano4ka [1.4K]

The angular momentum of an electron in the third Bohr orbit of a hydrogen atom is given by mvr=3h÷2π

<h3>What is momentum?</h3>

Momentum is defined as the amount of motion occurring in something that is moving, or the force that drives something forward to keep it moving.

Bohr never assumed stable electronic orbits with the electronic angular momentum quantized as

l=mvr = $\frac{nh}{2pi}$

Quantization of angular momentum means that the radius of the orbit and the energy will be quantized as well.

Bohr assumed that the discrete lines seen in the spectrum of the hydrogen atom were due to transitions of an electron from one allowed orbit/energy to another.

Learn more about momentum here:

https://brainly.in/question/38837394

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2 years ago