Question

We can overcome the undesirable properties of natural rubber by heating natural rubber with

• A. Carbon
• B. Sulphur
• C. Phosphorus
• D. Silicon

Hint:

The process of heating rubber with sulfur is called Vulcanization.
Remembering this term and its association with sulfur is key to answering questions about improving rubber's properties.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The aim is to determine the hardness level of the water sample in ppm based on the MgCl₂ present.

Step 2: Key Formula or Approach:
Calculate the CaCO₃ equivalent first and then express the result as mg/kg of water.

Step 3: Detailed Explanation:
Using the molar mass ratio, the CaCO₃ equivalent of 19 mg MgCl₂ is 20 mg. Dividing by the water mass of 2 kg gives 10 mg/kg. Since ppm equals mg/kg in water, the hardness is 10 ppm.

Step 4: Final Answer:
The hardness obtained is 10 ppm.