Concept explainers
Which of the following represent physical properties or changes, and which represent chemical properties or changes?
- You curl your hair with a curling iron.
(a)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Curling hair with a curling iron is a physical change.
Explanation of Solution
Curling iron with a curling iron does not make any change in fundamental components that make up hair. It just changes the appearance of hair which is a physical property. So curling up hair is a physical change.
(b)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Curling hair by getting a “permanent wave” is a chemical change.
Explanation of Solution
A permanent wave, involves the use of heat and chemicals to break and reform the cross-linking bonds of the hair structure. A chemical solution is applied on hair and this solution reacts chemically softening the inner structure of the hair by breaking some of the cross links within and between the protein chains of the hair. So getting permanent wave is a chemical change.
(c)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Melting of ice when salt is put on it is a physical change.
Explanation of Solution
Salt causes “freezing point depression”, i.e. salt helps in lowering the freezing point and, consequently, the melting point of water. Water freezes at 0°C or 32°F. By using salt, that freezing point can be lowered which causes the ice to melt.
(d)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Evaporating glass of water overnight is a physical change.
Explanation of Solution
When water evaporates, it changes its physical state from liquid state to the gaseous state. Evaporation of water does not make any change to the fundamental components of water, which is H2 O. So evaporation of water is a physical change.
(e)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Charring of steak, when the skillet gets too hot is a chemical change.
Explanation of Solution
When the skillet gets too hot, because of the high temperature, components of steak like proteins, carbohydrates are chemically changed. So the steak is no longer in its original form. So this is a chemical change.
(f)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Alcohol feels cool when it splits on skin due to a physical change.
Explanation of Solution
When alcohol splits on the skin, it evaporates quickly using the body temperature. Due to the sudden decrease of body temperature we feel cool. And because alcohol changes its physical state from liquid state to gaseous state, this is a physical change.
(g)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Ignition of alcohol is a chemical change.
Explanation of Solution
When alcohol ignites, it reacts with oxygen in the air and converted into carbon dioxide and water. So the components of alcohol are changed. So this is a chemical change.
(h)
Interpretation:
It should be discussed, that whether the given statement is a physical property or a change or chemical property or a change.
Concept Introduction:
Physical properties can be observed or measured without changing the composition of matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity etc. a physical change involves a change in one or more physical properties but no change in the fundamental components that make up the substance. The most common physical changes are changes of state: solid, liquid or gas.
A chemical change involves a change in the fundamental components of the substance; a given substance changes into a different substance or substances. Chemical changes are called reactions.
Answer to Problem 19CR
Baking powder causes the biscuits to rise due to a chemical change.
Explanation of Solution
Baking powder’s chemical name is sodium bicarbonate. When sodium carbonate and other materials are heated a chemical reaction undergoes and converts sodium bicarbonate into sodium carbonate, carbon dioxide and water. This carbon dioxide causes the biscuits to rise. So this is a chemical change.
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Chapter 3 Solutions
Student Solutions Manual for Zumdahl/DeCoste's Introductory Chemistry: A Foundation, 9th
- Write formulas for ionic compounds composed of the following ions. Use units as a guide to your solutions. 24. sodium and nitrate 25. calcium and chlorate 26. aluminum and carbonate 27. CHALLENGE Write the formula for an ionic compound formed by ions from a group 2 element and polyatomic ions composed of only carbon and oxygen.show work step by steparrow_forwardADDITIONAL PRACTICE PRACTICE Problems Write formulas for ionic compounds composed of the following ions. Use units as a guide to your solutions. 24. sodium and nitrate 25. calcium and chlorate 26. aluminum and carbonate 27. CHALLENGE Write the formula for an ionic compound formed by ions from a group 2 element and polyatomic ions composed of only carbon and oxygen. ounds 1998arrow_forward7:35 < Dji Question 19 of 22 5G 50% Submit What is the pH of a buffer made from 0.350 mol of HBrO (Ka = 2.5 × 10-9) and 0.120 mol of KBRO in 2.0 L of solution? | 1 2 3 ☑ 4 5 6 C 7 8 ☐ 9 +/- Tap here for additional resources ||| 0 ×10 Гarrow_forward
- aw the major substitution products you would expect for the reaction shown below. If substitution would not occur at a significant rate under these conditions, check the box underneath the drawing area instead. Be sure you use wedge and dash bonds where necessary, for example to distinguish between major products. Note for advanced students: you can assume that the reaction mixture is heated mildly, somewhat above room temperature, but strong heat or reflux is not used. B C Br HO O Substitution will not occur at a significant rate. Explanation Check + Х Click and drag to start drawing a structure. © 2025 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center | Accessibarrow_forwardComplete the following reactions with the necessary reagents to complete the shown transformation. Example: 1. 2. ? 3. 018 Br OH Answer: H₂O, H2SO4, HgSO4arrow_forward7:34 • < Question 18 of 22 5G 50% Submit What is the pH of a buffer made from 0.220 mol of HCNO (Ka = 3.5 × 10-4) and 0.410 mol of NaCNO in 2.0 L of solution? 1 2 3 ☑ 4 5 6 C 7 8 | 9 +/- 0 ×10 Tap here for additional resources ||| Гarrow_forward
- 6:46 ✔ 5G 58% < Question 7 of 22 Submit What is the primary species in solution at the halfway point in a titration of NH3 with HBr? A NH3 and H+ B NH₁+ and H+ C NH4+ D NH3 and NH4+ Tap here for additional resources |||arrow_forward6:49 Dji < Question 15 of 22 4G 57% Submit The pOH of a solution is 10.50. What is the OH- concentration in the solution? A 3.2 × 10-4 M B C 3.2 x 10-11 M 10.50 M D 4.2 M E 3.50 M Tap here for additional resources |||arrow_forwardヨ 6:49 Dji < Question 13 of 22 5G 57% Submit The pH of a solution is 2.40. What is the H+ concentration in the solution? A B 2.5 x 10-12 M 4.0 × 10-3 M C 2.40 M D 4.76 M 11.60 M Tap here for additional resources |||arrow_forward
- ヨ C 6:48 Di✔ < Question 12 of 22 5G 57% Submit The pH of a solution is 12.50. What is the H+ concentration in the solution? A 0.032 M B 3.2 × 10-13 M 1.5 M D 9.25 M 12.50 M Tap here for additional resources |||arrow_forwardヨ C 6:48 Di✔ < Question 11 of 22 5G 57% Submit The pH of a solution is 1.50. What is the H+ concentration in the solution? A 0.032 M B 3.2 × 10-13 M 1.5 M D 2.15 M 12.50 M Tap here for additional resources |||arrow_forwardSelect the product of the following reaction. Lon HO Meat ?? CH₂OH OH A D OH OCH B OH of OCH of CH חח E C CHarrow_forward
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