Q19
1 markMCQSection B

Magnesium ribbon burns with a dazzling white flame and changes into a white powder as shown in the diagram. The powder is dissolved in water. Identify the chemical formula of the white powder and the correct change observed when the solution is tested with litmus paper.

Figure for question 19
Chemical Reactions and Equations
Chemical Reactions and Equations

Options

(A)MgOMgO, turns blue litmus into red.
(B)MgOMgO, turns red litmus blue.
(C)MgO2MgO_2, turns red litmus blue.
(D)Mg2OMg_2O, turns blue litmus red.
Official Answer

The chemical formula of the white powder is MgO. When the solution is tested with litmus paper, it turns red litmus blue.

MgOturns red litmus blue

Marking Scheme

  • 1MgO
  • 2turns red litmus blue

Hint

The diagram shows that magnesium ribbon burns with a dazzling white flame and changes into a white powder. The powder is dissolved in water. The chemical formula of the white powder is MgO. When the solution is tested with litmus paper, it turns red litmus blue.

Quick Oral Answer

The chemical formula of the white powder is MgO. When the solution is tested with litmus paper, it turns red litmus blue.

Analysis & Explanation

The diagram shows that magnesium ribbon burns with a dazzling white flame and changes into a white powder. The powder is dissolved in water. The chemical formula of the white powder is MgO. When the solution is tested with litmus paper, it turns red litmus blue.

Common Mistakes

  1. 1MgO2
  2. 2turns blue litmus red

Interesting Facts

Magnesium ribbon burns with a dazzling white flame and changes into a white powder.

The powder is dissolved in water.

The chemical formula of the white powder is MgO.

When the solution is tested with litmus paper, it turns red litmus blue.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2026?

This question carries 1 mark in the CBSE Class 10 Science 2026 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Chemical Reactions and Equations" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Chemical Reactions and Equations" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2026 paper?

This is a MCQ question from Section B in the CBSE Class 10 Science 2026 paper.