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Ch.7 - Periodic Properties of the Elements

Chapter 7, Problem 115c

Potassium superoxide, KO2, is often used in oxygen masks (such as those used by firefighters) because KO2 reacts with CO2 to release molecular oxygen. Experiments indicate that 2 mol of KO2(s) react with each mole of CO2(g). (c) What mass of KO2(s) is needed to consume 18.0 g CO2(g)? What mass of O2(g) is produced during this reaction?

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Hi everyone. So here we have hydrogen gas rapping with chlorine gas to produce action chloride. We were asked to determine the mass of hydrogen gas that is required to react with 18.9 g of chlorine gas and were asked for the mass of hydrogen chloride produced. We have a church too, Plus c. L two and it's going to be on h C L. So to balance this, we need to put a two in front of hydrogen chloride and so now to find the mass of hydrogen gas, we need to convert from grams of chlorine gas, two g of hydrogen gas, you have 18 0.9 grams of chlorine gas And in one mole of chlorine gas, we have the molar mass which is to Times the mass of chlorine, which is 35 .453. And this gives us 70. and we have one mole of chlorine gas in the reaction. In one month of hydrogen gas in the reaction. And in one mold of hydrogen gas we have the molar mass and this is to Times the mass of hydrogen, which is 1.008. And this gives us 2.016. So we get 0.5, 37 grams of hash and gas. And now we need to find the mass of hydrogen chloride produced from the mass of either chlorine gas or hydrogen gas. So I have 18.9 g of chlorine gas and in one more Of chlorine gas have 70.91 g of chlorine gas. And we have one more of chlorine gas in the reaction, but two moles of hydrogen chloride in the reaction, And in one month of hydrogen chloride we have the molar mass, And this is 1.008 plus .453, And this gives us 36 .461. So we get 19.4 grams of hydrogen chloride. Thanks for watching my video, and I hope it was helpful.
Related Practice
Textbook Question
Mercury in the environment can exist in oxidation states 0, +1, and +2. One major question in environmental chemistry research is how to best measure the oxidation state of mercury in natural systems; this is made more complicated by the fact that mercury can be reduced or oxidized on surfaces differently than it would be if it were free in solution. XPS, X-ray photoelectron spectroscopy, is a technique related to PES (see Exercise 7.111), but instead of using ultraviolet light to eject valence electrons, X rays are used to eject core electrons. The energies of the core electrons are different for different oxidation states of the element. In one set of experiments, researchers examined mercury contamination of minerals in water. They measured the XPS signals that corresponded to electrons ejected from mercury's 4f orbitals at 105 eV, from an X-ray source that provided 1253.6 eV of energy 11 ev = 1.602 * 10-19J2. The oxygen on the mineral surface gave emitted electron energies at 531 eV, corresponding to the 1s orbital of oxygen. Overall the researchers concluded that oxidation states were +2 for Hg and -2 for O. (b) Compare the energies of the 4f electrons in mercury and the 1s electrons in oxygen from these data to the first ionization energies of mercury and oxygen from the data in this chapter.
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Textbook Question

When magnesium metal is burned in air (Figure 3.6), two products are produced. One is magnesium oxide, MgO. The other is the product of the reaction of Mg with molecular nitrogen, magnesium nitride. When water is added to magnesium nitride, it reacts to form magnesium oxide and ammonia gas. (c) In an experiment, a piece of magnesium ribbon is burned in air in a crucible. The mass of the mixture of MgO and magnesium nitride after burning is 0.470 g. Water is added to the crucible, further reaction occurs, and the crucible is heated to dryness until the final product is 0.486 g of MgO. What was the mass percentage of magnesium nitride in the mixture obtained after the initial burning?

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Textbook Question

When magnesium metal is burned in air (Figure 3.6), two products are produced. One is magnesium oxide, MgO. The other is the product of the reaction of Mg with molecular nitrogen, magnesium nitride. When water is added to magnesium nitride, it reacts to form magnesium oxide and ammonia gas. (d) Magnesium nitride can also be formed by reaction of the metal with ammonia at high temperature. Write a balanced equation for this reaction. If a 6.3-g Mg ribbon reacts with 2.57 g NH31g2 and the reaction goes to completion, which component is the limiting reactant? What mass of H21g2 is formed in the reaction?

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