The solubility of Zn(OH)2 in water at 25 °C is measured to be 4.2 × 101 Round your answer to 2 significant digits. L □×10 ⑤ Use this information to calculate KS, for Zn(OH)2. sp

ou place hot metal into a beaker of cold water. ol type='a'> Eventually what is true about the temperature of the metal compared to that of the water? Explain why this is true. i>Label this process as endothermic or exothermic if we consider the system to be the metal. Explain. the water. Explain.

9.96 Most first aid "cold packs" are based on the endothermic dissolution of ammonium nitrate in water: NH4NO3(s)NH4+(aq)+NO3(aq) H= 25.69 kJ A particular cold pack contains 50.0 g of NH4NO3 and 125.0 g of water. When the pack is squeezed, the NH4NO3dissolves in the water. If the pack and its contents are initially at 24.0°C, what is the lowest temperature that this bag could reach? (Assume that the ammonium nitrate solution has a specific heat of 4.25J g-l K-l, and that the heat capacity of the bag itself is small enough to be neglected.)

A student used a coffee-cup calorimeter to determine the enthalpy of solution for NH4NO3.When NH4NO3 is added to water, there is a decrease in temperature of the solution. Is the solution process exothermic or endothermic? (a) endothermic (b) exothermic

According to the Resource Conservation and Recovery Act (RCRA), waste material is classified as toxic and must be handled as hazardous if the lead concentration exceeds 5 mg/L. By adding chloride ion, the lead ion will precipitate as PbCl2, which can be separated from the liquid portion. Once the lead has been removed, the rest of the waste can be sent to a conventional waste treatment facility. How many grams of sodium chloride must be added to 500 L of a waste solution to reduce the concentration of the Pb2+ ion from 10 to 5 mg/L?

The following reaction occurs in pure water: H2O(l)+H2O(l)H3O+(aq)+OH-(aq) which is often abbreviated as H2O(l)H+(aq)+OH-(aq) For this reaction, G = 79.9 kJ/mol at 25C. Calculate the value of G for this reaction at 25C when [OH] = 0.15 M and [H+] = 0.71 M.

A rebreathing gas mask contains potassium superoxide, KO2, which reacts with moisture in the breath to give oxygen. 4KO2(s)+2H2O(l)4KOH(s)+3O2(g) Estimate the grams of potassium superoxide required to supply a persons oxygen needs for one hour. Assume a person requires 1.00 102 kcal of energy for this time period. Further assume that this energy can be equated to the heat of combustion of a quantity of glucose, C6H12O6, to CO2(g) and H2O(l). From the amount of glucose required to give 1.00 102 kcal of heat, calculate the amount of oxygen consumed and hence the amount of KO2 required. The ff0 for glucose(s) is 1273 kJ/mol.

Calculate H when a 38-g sample of glucose, C6H12O6(s), burns in excess O2(g) to form CO2(g) and H2O() in a reaction at constant pressure and 298.15 K.

xplain why aluminum cans make good storage containers for soft drinks. Styrofoam cups can be used to keep coffee hot and cola cold. How can this be?

The carbon dioxide exhaled in the breath of astronauts is often removed from the spacecraft by reaction with lithium hydroxide 2LiOH(s)+CO2(g)Li2CO3(s)+H2O(l) Estimate the grams of lithium hydroxide required per astronaut per day. Assume that each astronaut requires 2.50 103 kcal of energy per day. Further assume that this energy can be equated to the heat of combustion of a quantity of glucose, C6H12O6, to CO2(g) and H2O(l). From the amount of glucose required to give 2.50 103 kcal of heat, calculate the amount of CO2 produced and hence the amount of LiOH required. The H for glucose(s) is 1273 kJ/mol.