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3 years ago

A 5.60 g sample of a weak acid with

Chemistry

1 answer:

murzikaleks [220]3 years ago

4 0

Answer:

pKa = - log Ka = - log (1.3 * 10^-4) = 3.886 5.20 mL of 6.20 M NaOH = 0.00520 L * 6.20 mole…

Explanation:

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Which of the following describes the expected solubility of benzoic acid?

Igoryamba

I because it is an acid, it should be soluble in hexane

6 0

3 years ago

Calculate the number of atoms in 3 moles of carbon atoms

creativ13 [48]

Answer:

1,806,000,000,000,000,000,000,000 atoms.

Explanation:

1 mol of anything is 6.022*10^23 units

1 mol carbon atoms = 6.022*10^23 carbon atoms

3 mol carbon atoms = 3*6.022*10^23 = 1.8*10^24 atoms

Correctly - your answer should have only 1 significant digit: 2 * 10^24 atoms.

6 0

2 years ago

Calculate the pH of the solution that results when 20 mL of 0.2M HCOOH is mixed with 25mL of 0.2M NaOH solution.(post-equivalenc

Paul [167]

The pH of the solution : 12

<h3>Further explanation</h3>

Reaction

HCOOH + NaOH ⇒ HCOONa + H₂O

mol HCOOH =

$\tt 20~ml\times 0.2~M=4~mlmol$

mol NaOH =

$\tt 25~ml\times 0.2~M=5~mlmol$

Mol NaOH>mol HCOOH ⇒ at the end of the reaction there will be a strong base remains from mol NaOH, so that the pH is determined from [OH⁻]

ICE method :

HCOOH + NaOH ⇒ HCOONa + H₂O

4 5

4 4 4 4

0 1 1 1

Concentration of [OH⁻] from NaOH :

$\tt \dfrac{1~mlmol}{20+25~ml}=0.02$

pOH=-log[OH⁻]

pOH=-log 10⁻²=2

pH+pOH=14

pH=14-2=12

3 0

3 years ago

what is the minimum mass of ethylene glycol that must be dissolved in 14.5 kg of water to prevent the solution from freexing at

lbvjy [14]

Answer:

The minimum mass of ethylene glycol = 6.641 Kg

Explanation:

$\Delta T_f= T_f-T_f'\\T_f'=T_f-\Delta T_f$

Where T_f = freezing point of pure solvent water, 0°C

T_f'= Freezing point of solvent after mixture

K_f = Freezing point depression constant = 1.86 °C/m

Moecular weight of ethylene glycol = 60 g/mol

Weight of ethylene glycol = 14.5 Kg= 14.5×10^3 g

molality of ethylene glycol

$m = \frac{weight}{mol.wt} \times\frac{1000}{V}$

Substitute the values to calculate m

$m = \frac{w}{60} \times\frac{1000}{14.5\times1000}$

by formula

$0-(-14.2) =1.86\frac{w}{60} \times\frac{1000}{14.5\times1000}$

calculating we get w = 6641.93 g

Therefore, The minimum mass of ethylene glycol = 6.641 Kg

4 0

3 years ago

How is chemical change diferente from a physical change

laiz [17]

Chemical changes changes into a new substance and physical change can be reversed and just changes the form not the substance

8 0

3 years ago

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