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3 years ago

Calculate the enthalpies of formation, ΔHf∘, of the group 1 fluoride compounds from their elements using the Born–Haber cycle.

Chemistry

1 answer:

maxonik [38]3 years ago

5 0

Answer:

Enthalpy of formation of KF = -555 kJ/mol

Enthalpy of formation of CsF = -539kJ/mol

Explanation:

Explanations are provided in the attachment below

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To determine the specific heat capacity of copper, Alyssa performed an investigation by which she dropped a heated piece of copp

user100 [1]

Answer:

0.446

Explanation:

ccu = 3035.655 / 104 g x (98.9 - 33.5) = 0.446 J / g 0 C

6 0

2 years ago

If a buffer solution is 0.220 M in a weak acid ( Ka=7.4×10−5) and 0.540 M in its conjugate base, what is the pH?

valkas [14]

Answer: the pH of the solution is 4.52

Explanation:

Consider the weak acid as Ha, it is dissociated as expressed below

HA H⁺ + A⁻

the Henderson -Haselbach equation can be expressed as;

pH = pKa + log( [A⁻] / [HA])

the weak acid is dissociated into H⁺ and A⁻ ions in the solution.

now the conjugate base of the weak acid HA is

HA(aq) {weak acid} H⁺(aq) + A⁻(aq) {conjugate base}

so now we calculate the value of Kₐ as well as pH value by substituting the values of the concentrations into the equation;

pKₐ = -logKₐ

pKₐ = -log ( 7.4×10⁻⁵ )

pKₐ = 4.13

now thw pH is

pH = pKₐ + log( [A⁻] / [HA])

pH = 4.13 + log( [0.540] / [0.220])

pH = 4.13 + 0.3899

pH = 4.5199 = 4.52

Therefore the pH of the solution is 4.52

6 0

3 years ago

How many moles in 4.93 x 10E23 atoms of silver?

leva [86]

<h3>Answer:</h3>

0.819 mol Ag

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

4.93 × 10²³ atoms Ag

<u>Step 2: Identify Conversions</u>

Avogadro's Number

<u>Step 3: Convert</u>

Set up: $\displaystyle 4.93 \cdot 10^{23} \ atoms \ Ag(\frac{1 \ mol \ Ag}{6.022 \cdot 10^{23} \ atoms \ Ag})$
Divide: $\displaystyle 0.818665 \ mol \ Ag$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

0.818665 mol Ag ≈ 0.819 mol Ag

8 0

3 years ago

What energy is using the telephone?

kakasveta [241]

Answer:

electrical

Explanation:

i kinda guessed.

4 0

3 years ago

Read 2 more answers

Draw the structure of 1,4-hexanediamine.

brilliants [131]

Answer:

1,4-hexanediamine contains two $-NH_{2}$ functional groups.

Explanation:

1,4-hexanediamine is an organic molecule which contains two $-NH_{2}$ functional groups at C-1 and C-4 position.

The longest carbon chain in 1,4-hexanediamine contains six carbon atoms.

Molecular formula of 1,4-hexanediamine is $C_{6}H_{16}N_{2}$ .

1,4-hexanediamine used as a bidentate ligand in organometallic chemistry.

The structure of 1,4-hexanediamine is shown below.

5 0

3 years ago