_Cl2 + _NaBr → _NaCl + _Br2 Answer: 1,2,2,1

Suppose a student titrates a 10.00-ml aliquot of saturated ca(oh)2 solution to the equivalence point with 16.08 ml of 0.0199 m h

Alborosie

Following chemical reaction is involved upon titration of Ca(OH)2 with HCl,
Ca(OH)2 + 2HCl ↔ CaCL2 + 2H2O

Above is an example of acid-base titration to generate salt and water. Here, H+ ions of acid (HCl) combines with OH- (ions) of base [Ca(OH)2] to generated H2O

Given,
concentration of HCl = 0.0199 M
Total volume of HCl consumed during titration = 16.08 mL = 16.08 X 10^(-3) L

∴, number of moles of H+ consumed = Molarity X Vol. of HCl (in L)
= 0.0199 X 16.08 X 10^(-3)
= 3.1999 X 10^-4 mol
Thus, total number of moles of [OH-] ions present initial = 3.1999 X 10-4 mol
So, initial conc. [OH-] ion = $\frac{number of moles of [OH-]}{volume of solution (L)}$ = $\frac{3.1999 X 10^(^-^4^)}{10 X 10^(^-^3^)}$ = 0.03199 M

6 0

3 years ago

Potassium nitrate has a lattice energy of -163.8 kcal/mol and a heat of hydration of -155.5 kcal/mol.

Brut [27]

Answer:

293.99 g

OR

0.293 Kg

Explanation:

Given data:

Lattice energy of Potassium nitrate (KNO3) = -163.8 kcal/mol

Heat of hydration of KNO3 = -155.5 kcal/mol

Heat to absorb by KNO3 = 101kJ

To find:

Mass of KNO3 to dissolve in water = ?

Solution:

Heat of solution = Hydration energy - Lattice energy

= -155.5 -(-163.8)

= 8.3 kcal/mol

We already know,

1 kcal/mol = 4.184 kJ/mole

Therefore,

= 4.184 kJ/mol x 8.3 kcal/mol

= 34.73 kJ/mol

Now, 34.73 kJ of heat is absorbed when 1 mole of KNO3 is dissolved in water.

For 101 kJ of heat would be

= 101/34.73

= 2.908 moles of KNO3

Molar mass of KNO3 = 101.1 g/mole

Mass of KNO3 = Molar mass x moles

= 101.1 g/mole x 2.908

= 293.99 g

= 0.293 kg

293.99 g potassium nitrate has to dissolve in water to absorb 101 kJ of heat.

4 0

3 years ago

Which of the following might a chemist choose to study?

Serjik [45]

Answer:

B. Better ways to recycle plastics

Explanation:

A chemist might choose to study better ways to recycle plastics because there may be certain types of chemicals that can disintegrate the plastic..

7 0

2 years ago

Which of the following is an example of erosion?

Drupady [299]

Answer:

Glaciers moving rocks and soil through a valley

Explanation:

The definition of Erosion is "the process of eroding or being eroded by wind, water, or other natural agents". Which in turn means the movement of glaciers is causing erosion on the local valley.

6 0

3 years ago

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When a student combed his dry hair for a long time, his hair began to stand up. Which of these has MOST LIKELY happened? A) The

Alecsey [184]

B.

Opposites attract, likes repel.

5 0

3 years ago

Read 2 more answers