Answer:The green growing on the penny of copper and the rust forming on the nail of iron are chemical changes. Boiling away salt water, scraping iron filings from a mixture of sand with a magnet, and breaking a rock with a hammer, are physical changes.
Explanation:
City B is at a higher temperature because as you go higher in altitude the boiling point of water becomes lower.
% composition of ethanol = 34.51%
% composition of water = 65.49%
<h3>What is density?</h3>
A material's density is defined as its mass per unit volume.
Given data:
The density of ethanol = 0.7890 g/mL
The density of water = 0.9982 g/mL
The density of mixture = 0.926 g/mL
Let the % composition of ethanol = x
Let the % composition of water = 100-x
Now density of the mixture
%
Hence,
% composition of ethanol = 34.51%
% composition of water = 65.49%
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.A solution that serves as a pH indicator may be made using red cabbage, which is frequently available in homes. In essence, the color of the cabbage depends on the acidity of the solution and a pigment molecule called flavin or anthocyanin.
To determine whether a material is an acid or a base, red cabbage indicator is a purple-colored solution
Vinegar is an acid and its pH value is less than 7 and hence
Red color is produced
Baking soda is base and its pH value is greater than 7 and between 8-9
and the color produced is sky blue
Bleach is the green which is also a basic and because the pH value is 10-11
Householder cleaner is having pH 11-13 which is basic and hence the yellow is the color of household cleaner .
A basic solution goes away from being basic and toward the center of the pH scale when an acid is introduced. The base is "neutralized" in this manner.
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