All categories

2 years ago

Why was methyl red used as an indicator in this experiment rather than phenolphthalein?

1 answer:

8 0

Methyl Red, also called C.I. Acid Red 2, is an indicator dye that turns red in acidic solutions.
Phenolphthalein is a sensitive chemical with the formula C20H14O4 (often written as "HIn" in chemistry shorthand notation). Often used in titrations, it turns from colorless in acidic solutions to pink in basic solutions. If the concentration of indicator is particularly strong, it can appear purple. A phenolphtalein turns a bright orange color, in a solution containing a ph below 0.

You might be interested in

Write the balanced Ka and Kb reactions for HSO3- in water. Be sure to include the physical states of each species involved in th

Hunter-Best [27]

Answer:

Ka = [H₃O⁺] [SO₃²⁻] / [HSO₃⁻]

Kb = [OH⁻] [H₂SO₃] / [HSO₃⁻]

Explanation:

An amphoteric substance as HSO₃⁻ is a substance that act as either an acid or a base. When acid:

HSO₃⁻(aq) + H₂O(l) ⇄ H₃O⁺(aq) + SO₃²⁻(aq)

And Ka, the acid dissociation constant is:

When base:

HSO₃⁻(aq) + H₂O(l) ⇄ OH⁻(aq) + H₂SO₃(aq)

And kb, base dissociation constant is:

6 0

1 year ago

Consider the solutions, 0.04 m urea [(NH2)2C=O)], 0.04 m AgNO3 and 0.04 m CaCl2. Which has (i) the highest osmotic pressure, (ii

Lana71 [14]

Answer:

i) Highest osmotic pressure: CaCl2

ii) lower vapor pressure : CaCl2

iii) highest boiling point : CaCl2

Explanation:

The colligative properties depend upon the number of solute particles in a solution.

The following four are the colligative properties:

a) osmotic pressure : more the concentration of the solute, more the osmotic pressure

b) vapor pressure: more the concentration of the solute, lesser the vapor pressure.

c) elevation in boiling point: more the concentration of the solute, more the boiling point.

d) depression in freezing point: more the concentration of the solute, lesser the freezing point.

the number of particle produced by urea = 1

the number of particle produced by AgNO3 = 2

the number of particle produced by CaCl2 = 3

As concentrations are same, CaCl2 will have more number of solute particles and urea will have least

i) Highest osmotic pressure: CaCl2

ii) lower vapor pressure : CaCl2

iii) highest boiling point : CaCl2

5 0

2 years ago

12. The most common factors that cause chemical reactions to occur are all the following except

ruslelena [56]

Transfer of electrons

6 0

2 years ago

How many grams of CaF2 are present in 1.25 L of a 0.15 M solution of CaF2? How do I find the grams I am confused on that part?

dybincka [34]

Answer:

Mass = 14.64 g

Explanation:

Given data:

Volume of solution = 1.25 L

Molarity of Solution = 0.15 M

Mass of CaF₂ = ?

Solution:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

We will calculate the number of moles of CaF₂ and then determine the mass by using number of moles.

0.15 M = number of moles of solute / 1.25 L

number of moles of solute = 0.15 M × 1.25 L

number of moles of solute = 0.1875 mol/L × L

number of moles of solute = 0.1875 mol

Mass in gram:

Mass = number of moles × molar mass

Mass = 0.1875 mol ×78.07 g/mol

Mass = 14.64 g

7 0

2 years ago

nevsk [136]

Answer:

C4H90H

Explanation:

nskwjxnxnxnslq

6 0

2 years ago