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3 years ago

How many moles of PBr3 contain 3.68 x 10^25 bromine atoms?

2 answers:

7 0

3.68 x 10²⁵ bromine atoms * 1mol/6.02*10²³ atoms=
= 61.13 mol of bromine atoms

1 mol PBr3 ----- 3 mol Br
x mol PBr3 -----61.13 mol Br

x= 1*61.13/3 = 20.4 mol PBr3.

20.4 mol PBr3 contain 3.68 x 10^25 bromine atoms.

emmainna [20.7K]3 years ago

3 0

Answer:

20.4 moles of $PBr_{3}$ contain $3.68\times 10^{25}$ bromine atoms

Explanation:

1 molecule of $PBr_{3}[/tex contains one P atom and three Br atomsSo 1 mol of [tex]PBr_{3}[/tex contains 3 moles of Br.We know that 1 mol = [tex]6.023\times 10^{23}$ molecules

So, there are $(3\times 6.023\times 10^{23})$ atoms of Br in 1 mol of $PBr_{3}$

Hence $3.68\times 10^{25}$ bromine atoms are present in $\frac{3.68\times 10^{25}}{3\times 6.023\times 10^{23}}$ moles of $PBr_{3}$ or 20.4 moles of $PBr_{3}$

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A sample of pure NO2 is heated to 335 ∘C at which temperature it partially dissociates according to the equation 2NO2(g)⇌2NO(g)+

vodka [1.7K]

The equilibrium constant for the reaction is 0.00662

Explanation:

The balanced chemical equation is :

2NO2(g)⇌2NO(g)+O2(g

At t=t 1-2x ⇔ 2x + x moles

The ideal gas law equation will be used here

PV=nRT

here n= $\frac{w}{W}$ = $\frac{w}{V}$ = density

P = $\frac{density RT}{M}$ density is 0.525g/L, temperature= 608.15 K, P = 0.750 atm

putting the values in reaction

0.75 = $\frac{0.525 x 0.0821 x 608.15 }{M}$

M = 34.61

to calculate the Kc

Kc= $\frac{ [NO] [O2]}{NO2}$

$\frac{1-2x}{1+x}$ x M NO2 + $\frac{2x}{1+x}$ M NO+ $\frac{x}{1+x}$ M O2

Putting the values as molecular weight of NO2, NO,O2

$\frac{46(1-2x) +30(2x)+32x}{1+x}$

34.61= $\frac{46}{1+x}$

x= 0.33

Kc= $\frac{4x^2)x}{1-2x^2}$

putting the values in the above equation

Kc = 0.00662

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3 years ago

Zingerone, one of the flavor molecules in ginger,

MissTica

The molecular formula of the compound is C12H15O3 hence the molar mass of the compound is 207 g/mol.

We need to obtain the number of moles of carbon, hydrogen and oxygen in the compound;

Carbon = 24.91 g/44g/mol × 1 mole of carbon = 0.566 moles

Mass of carbon = 0.566 moles × 12 g/mol = 6.792 g

Number of moles of hydrogen = 6.522 g/18 g/mol × 2 moles = 0.725 moles

Mass of hydrogen = 0.725 moles × 1 g/mol = 0.725 g

Mass of oxygen = 10 - (6.792 g + 0.725 g) = 2.483 g

Number of moles of oxygen = 2.483 g/16 g/mol = 0.155 moles

Now we must divide through by the lowest number of moles;

C - 0.566/0.155 H - 0.725/0.155 O - 0.155/0.155

C - 4 H - 5 O - 1

The simplest formula is C4H5O Recall that the molar mass of the compound lies between 150.0 and 220.0 g/mol

4(12) + 5(1) + 16 = 69

Hence; n = 3 and the molecular formula of the compound is C12H15O3

The molar mass of the compound is; 12(12) + 15(1) + 3(16) = 207 g/mol

Learn more: brainly.com/question/15180604

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3 years ago

What coefficient should be placed before 02? 2S+ __02 → 2S03

Trava [24]

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3 years ago

Ca (ClO) 2 Spell out the full name of the compound.

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4 years ago

Calculate the pka of hypochlorous acid. The ph of a 0.015 m solution of hypochlorous acid has a ph of 4.64.

o-na [289]

Answer:

pKa = 7.46

Explanation:

1) Data:

a) Hypochlorous acid = HClO

b) [HClO} = 0.015

c) pH = 4.64

d) pKa = ?

2) Strategy:

With the pH calculate [H₃O⁺], then use the equilibrium equation to calculate the equilibrium constant, Ka, and finally calculate pKa from the definition.

3) Solution:

a) pH

pH = - log [H₃O⁺]

4.64 = - log [H₃O⁺]

$[H_3O^+]= 10^{-4.64} = 2.29.10^{-5}$

b) Equilibrium equation: HClO (aq) ⇄ ClO⁻ (aq) + H₃O⁺ (aq)

c) Equilibrium constant: Ka = [ClO⁻] [H₃O⁺] / [HClO]

d) From the stoichiometry: [CLO⁻] = [H₃O⁺] = 2.29 × 10 ⁻⁵ M

e) By substitution: Ka = (2.29 × 10 ⁻⁵ M)² / 0.015M = 3.50 × 10⁻⁸ M

f) By definition: pKa = - log Ka = - log (3.50 × 10 ⁻⁸) = 7.46

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