Chapter 5 – Review
5.1 Early Atomic Theory: Dalton’s Model of the Atom
- In the following drawing, the green, larger spheres represent atoms of a certain element. The blue, smaller spheres represent atoms of another element. If the spheres of different elements touch, they are part of a single unit of a compound. The following chemical change represented by these spheres may violate one of the ideas of Dalton’s atomic theory. Which one?Check Answer: [1]
- Which postulate of Dalton’s theory is consistent with the following observation concerning the weights of reactants and products? When 100 grams of solid calcium carbonate is heated, 44 grams of carbon dioxide and 56 grams of calcium oxide are produced.
Check Answer: [2] - Identify the postulate of Dalton’s theory that is violated by the following observations: 59.95% of one sample of titanium dioxide is titanium; 60.10% of a different sample of titanium dioxide is titanium. Check Answer: [3]
- Samples of compound X, Y, and Z are analyzed, with results shown in the data table below.
Qualitative and Quantitative Analysis of Compounds X, Y, Z Compound Description Mass of Carbon Mass of Hydrogen X clear, colourless, liquid with strong odour 1.776 g 0.148 g Y clear, colourless, liquid with strong odour 1.974 g 0.329 g Z clear, colourless, liquid with strong odour 7.812 g 0.651 g Do these data provide example(s) of the law of definite proportions, the law of multiple proportions, neither, or both? What do these data tell you about compounds X, Y, and Z? Check Answer: [4]
- For the following questions, state whether the statement regarding Dalton’s Atomic Theory is True or False. If it is false, provide the correct word or phrase for the bolded term to make that statement true.
- According to Dalton’s Atomic Theory, matter consists of indivisible particles called atoms.
- Dalton’s Atomic Theory postulates mass is neither created nor destroyed in a chemical reaction. This supports the law of constant proportions.
- According to Dalton’s atomic theory, all atoms of a given element have identical properties including identical mass.
- Two of Dalton’s postulates include (1) matter is composed of exceedingly small, indivisible particles and (2) elements consist of only one type of identical atom, which has the same mass for all atoms. These two theories have been proven to be valid theories by later scientists.
Check Answer: [5]
5.2 Electric Charge
- For the following questions, state whether the statement regarding electric charge is True or False. If it is false, provide the correct word or phrase for the bolded term to make that statement true.
- Electric charges can be positive and negative.
- Electric force can be either be equal or repulsive.
- If two interacting objects carry opposite charges, it results in electrostatic repulsion.
- A balloon is rubbed on hair to gain charge. Then the comb is placed near running water from a tap. You observe that the stream of water is bending towards the comb. You