The metal cadmium tends to form \(\mathrm{Cd}^{2+}\) ions. The following observations are made:
(i) When a strip of zinc metal is placed in \(\mathrm{CdCl}_{2}(a q)\), cadmium metal is deposited on the strip.
(ii) When a strip of cadmium metal is placed in \(\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{2}(a q)\), nickel metal is deposited on the strip.
(a) Write net ionic equations to explain each of the preceding observations.
(b) Which elements more closely define the position of cadmium in the activity series?
(c) What experiments would you need to perform to locate more precisely the position of cadmium in the activity series?
Text Transcription:
Cd2+
CdCl21aq)
Ni(NO3)2(aq)
Step 1 of 5) Fuel values for some common foods are shown in Table 5.5. Labels on packaged foods show the amounts of carbohydrate, fat, and protein contained in an average serving, as well as the amount of energy supplied by a serving (Figure 5.25). The amount of energy our bodies require varies considerably, depending on such factors as weight, age, and muscular activity. About 100 kJ per kilogram of body mass per day is required to keep the body functioning at a minimal level. An average 70-kg (154-lb) person expends about 800 kJ>h when doing light work, and strenuous activity often requires 2000 kJ>h or more. When the fuel value, or caloric content, of the food we ingest exceeds the energy we expend, our body stores the surplus as fat.Analyze (a) The fuel value of the serving will be the sum of the fuel values of the protein, carbohydrates, and fat. (b) Here we are faced with the reverse problem, calculating the quantity of food that provides a specific fuel value. Plan (a) We are given the masses of the protein, carbohydrates, and fat contained in a serving. We can use the data in Table 5.4 to convert these masses to their fuel values, which we can sum to get the total fuel value. (b) The problem statement provides a conversion factor between Calories and miles. The answer to part (a) provides us with a conversion factor between servings and Calories.
