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3 years ago

What are the first few items you should evaluate when reading a graph”?

Chemistry

2 answers:

antiseptic1488 [7]3 years ago

8 0

Answer:

punctuation, and if it makes sense

kati45 [8]3 years ago

4 0

Title, axes, increments, labels, and scale

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When the process of condensation occurs, the kinetic energy of particles.

amm1812

Answer:

Is insufficient to overcome intermolecular forces.

Explanation:

Hope this helps

Please let me know if I'm wrong

5 0

2 years ago

In full detail, explain what happens during the electrolysis of a NaCl brine? Be sure to identify what is being oxidized and wha

yuradex [85]

Answer:

Explanation:

Electrolysis of aqeous sodium chloride(NaCl)

Electrolysis is a process that converts electrical energy into chemical energy.

Electrolytic processes involves three major steps:

1. Ionization of electrolyte and water

2. Migration of ions to electrodes

3. Discharge of ions at the electrodes.

For the Electrolysis of brine, we follow these three steps:

1. Ionization of the aqeous brine solution:

NaCl → Na⁺ + Cl⁻

H₂O ⇄H⁺ + OH⁻

2. Migration of ions to the electrodes

The positive charges Na⁺ and H⁺ would both go to the cathode which is the negatively charged electrode

The negative charges Cl⁻ and OH⁻ migrates to the anode which are the positively charged electrodes. The anode is positively charged electrode.

3. Discharge of ions at the electrodes.

The preferential discharge of ions is based on the activity series and concentration of the ions.

On the activity series H is lower and it discharges preferentially to Na in the cathode:

2H⁺ + 2e⁻ → H₂

At this electrode, the cathode, reduction occurs and H⁺ ions are reduced.

At the anode Cl⁻ and OH⁻ migrates. But Cl⁻ is discharged preferentially due to its higher concentration.

2Cl⁻ ⇄ Cl₂ + 2e⁻

This is the oxidation half and Cl is oxidized

3 0

3 years ago

4. Which of the following methods of preserving food keeps food for long without going bad by making bacteria inactive? A. Freez

maw [93]

Answer:

c. because it lacks oxygen which might support life of the bacteria

6 0

2 years ago

A chemist prepares a solution of zinc nitrate Zn(NO3)2 by measuring out 78.3g of zinc nitrate into a 350ml volumetric flask and

Anvisha [2.4K]

Answer:

M = 1.18 mol/L

Explanation:

Moles is denoted by given mass divided by the molecular mass ,

Hence ,

$n = \frac{w}{n}$

n = moles ,

w = given mass ,

m = molecular mass .

From the information of the question ,

w = 78.3 g

As we known ,

molecular mass of $Zn(NO_3)_2$ is 189.36 g/mol

m = 189.36 g/mol

moles can be calculated as -

$n = \frac{w}{n}$

$n = \frac{78.3g}{189.36 g/mol}$

n = 0.413 mol

MOLARITY -

Molarity of a substance , is the number of moles present in a liter of solution .

$M=\frac{n}{V}$

M = molarity ( unit = mol / L or M )

V = volume of solution in liter ( unit = L ),

n = moles of solute ( unit = mol ),

From the question ,.

V = 350 mL

Since , 1 mL = 10⁻³ L

V = 0.350 L

n = 0.413 mol

Molarity can be calculated as -

$M=\frac{n}{V}$

$M=\frac{0.413}{0.350}$

M = 1.18 mol/L

6 0

3 years ago

What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4? Hint: The pKa of phosphate is 6.86.

AlekseyPX

Answer:

The pH value of the mixture will be 7.00

Explanation:

Mono and disodium hydrogen phosphate mixture act as a buffer to maintain pH value around 7. Henderson–Hasselbalch equation is used to determine the pH value of a buffer mixture, which is mathematically expressed as,

$pH=pK_{a} + log(\frac{[Base]}{[Acid]})$

According to the given conditions, the equation will become as follow

$pH=pK_{a} + log(\frac{[Na_{2}HPO_{4} ]}{[NaH_{2}PO_{4}]})$

The base and acid are assigned by observing the pKa values of both the compounds; smaller value means more acidic. NaH₂PO₄ has a pKa value of 6.86, while Na₂HPO₄ has a pKa value of 12.32 (not given, but it's a constant). Another more easy way is to the count the acidic hydrogen in the molecular formula; the compound with more acidic hydrogens will be assigned acidic and vice versa.

Placing all the given data we obtain,

$pH=6.86 + log(\frac{0.058}{0.042})$

$pH=7.00$

5 0

4 years ago