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11 Nov 2019
Please answer the questions 2-6 on the last 2 pictures by reading the first 5 pictures.
EXPERIMENT 4 ll the Preparation and Properties of Hydrogen t mou MATERIALS AND EQUIPMENT splints. Solids: strips of copper, magnesium, and zine; steel wool; mossy zine; wood Solutions dilute (6 M) acetic acid (HC,HO. 0.1 M coppertID sulfate (Cusdh dilute (6 M) hydrochlorie acid (HCD, dilute (3 AD phosphoric acid (H,PO),9 M sulfuri CHSO) and dilute (3 MD sulfuric acid (HSO), phenolphthalein solution. Pneumatie wide-mouth (gas-collecting) bottles, five glass cover plates, pÅH paper. DISCUSSION Hydrogen, having atomie number 1 and atomic mass 1.008 amu, is the simplest element. It is the ninth most abundant element in the earth's crust (about 0.9 percent by ma88). At ordi- nary temperatures and pressures it is a gas, composed of diatomic molecules, H, and is only very slightly soluble in water. Hydrogen is usually found combined with other elements Water is the most common and probably the most important compound of hydrogen. Hydrogen will not support combustion, but in the presence of oxygen it burns readily to form in air water: in the first l that This reaction is used as a simple test for hydrogen, for mixtures of hydrogen and air (or oxygen) burn explosively with a distinctive "popping" or "barking sound. A. Preparing Hydrogen There are several ways of producing hydrogen gas. The method used in this experiment involves the formation of hydrogen from aqueous solutions containing hydrogen ions (H'). The concentration of hydrogen ions in solution is often expressed as pH. pH is a numerical scale corresponding to the acidity of a solution. Pure water at 25 C is neither acidice nor basic and is given a pH of 7 on the pH scale. pH values less than 7 indicate an acidic solution; the lower the number, the more acidic the solution. pH values greater than 7 indicate a basic solu- tion; the larger the number the more basic the solution. ext ttle ht pH 7 = base solutions It is possible to determine whether a solution is acidic or basic by using acid-base indica- tors such as litmus or phenolphthalein. However, these indicators do not give very precise information. It is also possible to get more precise hydrogen ion concentrations using pH pape In this experiment you will measure the pEH of several acids and compare the relationship of their pH values to the strength of the acids and the rate of hydrogen formation. r strips impregnated with several indicators, or with an instrument called a pH meter -37-
Please answer the questions 2-6 on the last 2 pictures by reading the first 5 pictures.
EXPERIMENT 4 ll the Preparation and Properties of Hydrogen t mou MATERIALS AND EQUIPMENT splints. Solids: strips of copper, magnesium, and zine; steel wool; mossy zine; wood Solutions dilute (6 M) acetic acid (HC,HO. 0.1 M coppertID sulfate (Cusdh dilute (6 M) hydrochlorie acid (HCD, dilute (3 AD phosphoric acid (H,PO),9 M sulfuri CHSO) and dilute (3 MD sulfuric acid (HSO), phenolphthalein solution. Pneumatie wide-mouth (gas-collecting) bottles, five glass cover plates, pÅH paper. DISCUSSION Hydrogen, having atomie number 1 and atomic mass 1.008 amu, is the simplest element. It is the ninth most abundant element in the earth's crust (about 0.9 percent by ma88). At ordi- nary temperatures and pressures it is a gas, composed of diatomic molecules, H, and is only very slightly soluble in water. Hydrogen is usually found combined with other elements Water is the most common and probably the most important compound of hydrogen. Hydrogen will not support combustion, but in the presence of oxygen it burns readily to form in air water: in the first l that This reaction is used as a simple test for hydrogen, for mixtures of hydrogen and air (or oxygen) burn explosively with a distinctive "popping" or "barking sound. A. Preparing Hydrogen There are several ways of producing hydrogen gas. The method used in this experiment involves the formation of hydrogen from aqueous solutions containing hydrogen ions (H'). The concentration of hydrogen ions in solution is often expressed as pH. pH is a numerical scale corresponding to the acidity of a solution. Pure water at 25 C is neither acidice nor basic and is given a pH of 7 on the pH scale. pH values less than 7 indicate an acidic solution; the lower the number, the more acidic the solution. pH values greater than 7 indicate a basic solu- tion; the larger the number the more basic the solution. ext ttle ht pH 7 = base solutions It is possible to determine whether a solution is acidic or basic by using acid-base indica- tors such as litmus or phenolphthalein. However, these indicators do not give very precise information. It is also possible to get more precise hydrogen ion concentrations using pH pape In this experiment you will measure the pEH of several acids and compare the relationship of their pH values to the strength of the acids and the rate of hydrogen formation. r strips impregnated with several indicators, or with an instrument called a pH meter -37-
Nestor RutherfordLv2
2 Nov 2019