Exam Review
... 3. An oxide of nitrogen was found to contain 36.8% nitrogen by mass. a) Find the empirical formula for this compound. (N2O3) b) The molar mass of this compound was found to be 76.02 g/mol. What is the molecular formula of this compound? (N2O3) 4. A compound contains 16.0 g of hydrogen and 96.0 g of ...
... 3. An oxide of nitrogen was found to contain 36.8% nitrogen by mass. a) Find the empirical formula for this compound. (N2O3) b) The molar mass of this compound was found to be 76.02 g/mol. What is the molecular formula of this compound? (N2O3) 4. A compound contains 16.0 g of hydrogen and 96.0 g of ...
Document
... (c) The orders of proton number and relative atomic mass for these five elements are different. Which one of the following is the most likely explanation for this? Tick one box. The proton number of a particular element may vary. ...
... (c) The orders of proton number and relative atomic mass for these five elements are different. Which one of the following is the most likely explanation for this? Tick one box. The proton number of a particular element may vary. ...
AS Paper 1 Practice Paper 4 - A
... The student decided to use a measuring cylinder to obtain 25.0 cm3 of the supplier’s solution. This was poured into a 250 cm3 graduated flask and the liquid level was made up to the mark with de-ionised water. The student filled a burette with the acid solution. The following results were obtained w ...
... The student decided to use a measuring cylinder to obtain 25.0 cm3 of the supplier’s solution. This was poured into a 250 cm3 graduated flask and the liquid level was made up to the mark with de-ionised water. The student filled a burette with the acid solution. The following results were obtained w ...
Name ……………………………..………...… …….. Index No
... b) 20g of potassium chloride were placed in a glass beaker and 40.0cm3 of water were added. The beaker was heated until all the potassium chloride had dissolved and then allowed to cool. When crystals first appear the temperature was noted. An extra 5.0cm3 of water were added and the experiment was ...
... b) 20g of potassium chloride were placed in a glass beaker and 40.0cm3 of water were added. The beaker was heated until all the potassium chloride had dissolved and then allowed to cool. When crystals first appear the temperature was noted. An extra 5.0cm3 of water were added and the experiment was ...
CHM 212 - The Federal University of Agriculture, Abeokuta
... Bromides and iodides occur in much smaller amounts than either fluorides or chlorides. Sea water contains only small concentration of bromine(Br2) but significantly higher concentrations of Br- are present in salt lakes and natural brine wells. The natural abundance of iodine is less than that of th ...
... Bromides and iodides occur in much smaller amounts than either fluorides or chlorides. Sea water contains only small concentration of bromine(Br2) but significantly higher concentrations of Br- are present in salt lakes and natural brine wells. The natural abundance of iodine is less than that of th ...
Conservation of Mass Lab
... during a chemical reaction. This means that all chemical reactions must be balanced—the number of atoms, moles, and ultimately the total mass must be conserved during a chemical process. Here are the rules to follow when balancing equations: ...
... during a chemical reaction. This means that all chemical reactions must be balanced—the number of atoms, moles, and ultimately the total mass must be conserved during a chemical process. Here are the rules to follow when balancing equations: ...
Intro To Atomic Theory
... • Ion: If electrons are added or removed from a neutral atom, then it is called an ion ...
... • Ion: If electrons are added or removed from a neutral atom, then it is called an ion ...
Section A oxide in molten cryolite?
... Q1 In the extraction of aluminium by electrolysis, why is it necessary to dissolve aluminium oxide in molten cryolite? A to reduce the very high melting point of the electrolyte B cryolite provides the ions needed to carry the current C cryolite reacts with the aluminium oxide to form ions D molten ...
... Q1 In the extraction of aluminium by electrolysis, why is it necessary to dissolve aluminium oxide in molten cryolite? A to reduce the very high melting point of the electrolyte B cryolite provides the ions needed to carry the current C cryolite reacts with the aluminium oxide to form ions D molten ...
Answer Key
... E) 42 g 9. The mass of 1.63 1021 silicon atoms is A) 1.04 104 g. B) 28.08 g. C) 2.71 10–23 g. D) 7.60 10–2 g. E) 4.58 1022 g. ...
... E) 42 g 9. The mass of 1.63 1021 silicon atoms is A) 1.04 104 g. B) 28.08 g. C) 2.71 10–23 g. D) 7.60 10–2 g. E) 4.58 1022 g. ...
Word and Skeleton Equations Practice (ws Fall 2010)
... 1. Gaseous hydrogen and oxygen react to form gaseous water. 2. Solid sodium metal reacts with liquid water to form an aqueous solution of sodium hydroxide and hydrogen gas. 3. Solid potassium chlorate breaks down to form solid potassium chloride and oxygen gas. 4. Solid copper reacts with oxygen gas ...
... 1. Gaseous hydrogen and oxygen react to form gaseous water. 2. Solid sodium metal reacts with liquid water to form an aqueous solution of sodium hydroxide and hydrogen gas. 3. Solid potassium chlorate breaks down to form solid potassium chloride and oxygen gas. 4. Solid copper reacts with oxygen gas ...
Cyanide Destruction with Chlorine Dioxide
... treatment of cyanides in wastewater. Oxidation should be considered when levels of oxidizable cyanide are too high to be processed by a biological treatment system. Chlorine dioxide Chlorine dioxide is unique in its ability to be used at moderately basic pH's. All other oxidants require pH's greater ...
... treatment of cyanides in wastewater. Oxidation should be considered when levels of oxidizable cyanide are too high to be processed by a biological treatment system. Chlorine dioxide Chlorine dioxide is unique in its ability to be used at moderately basic pH's. All other oxidants require pH's greater ...
Oxidation Number Rules
... c. Hydrogen usually has an oxidation number of +1 except in metallic hydrides where it then has an oxidation number of -1 Examples: HCl, hydrogen is +1; NaH, hydrogen is -1. d. The halogens, unless bonded to an element with a higher electronegativity, have an oxidation number of -1. Examples: NaCl, ...
... c. Hydrogen usually has an oxidation number of +1 except in metallic hydrides where it then has an oxidation number of -1 Examples: HCl, hydrogen is +1; NaH, hydrogen is -1. d. The halogens, unless bonded to an element with a higher electronegativity, have an oxidation number of -1. Examples: NaCl, ...
Guidelines for the Use of Chlorine Bleach as a
... part by pH. This is because when sodium hypochlorite (NaOCl) is mixed with water an equilibrium reaction between hypochlorite and hypochlorous acid (HOCl, the active sanitizing agent) occurs. This reaction occurs as follows: First, the NaOCl dissolves and chemically breaks apart in the water. ...
... part by pH. This is because when sodium hypochlorite (NaOCl) is mixed with water an equilibrium reaction between hypochlorite and hypochlorous acid (HOCl, the active sanitizing agent) occurs. This reaction occurs as follows: First, the NaOCl dissolves and chemically breaks apart in the water. ...
SCH3U - Norbraten
... Zinc metal and a solution of lead (II) nitrate react to form a solution of zinc nitrate and solid lead. Aluminum bromide salt and chlorine gas react to form aluminum chloride crystals and bromine gas. Aqueous solutions of sodium phosphate and calcium chloride react to form solid calcium phosphate an ...
... Zinc metal and a solution of lead (II) nitrate react to form a solution of zinc nitrate and solid lead. Aluminum bromide salt and chlorine gas react to form aluminum chloride crystals and bromine gas. Aqueous solutions of sodium phosphate and calcium chloride react to form solid calcium phosphate an ...
Practice Test 11 - U of L Class Index
... A chunk of white phosphorus weighing 6.58 grams is put in a 750 mL flask containing dry argon (which is then removed using a vacuum, leaving only the phosphorus in the flask). A separate 750 mL flask contains 3.15 bar of fluorine gas (at 19.65 °C). The two flasks are connected so that the two compou ...
... A chunk of white phosphorus weighing 6.58 grams is put in a 750 mL flask containing dry argon (which is then removed using a vacuum, leaving only the phosphorus in the flask). A separate 750 mL flask contains 3.15 bar of fluorine gas (at 19.65 °C). The two flasks are connected so that the two compou ...
Cl Cl and
... many electrons does each nucleus of chlorine “feel” going around it? How does this number compare to the number of electrons around the nucleus of the next noble gas? 18, the same. 12. Give, in your own words, an explanation for the fact that the element chlorine at room temperature exists as diatom ...
... many electrons does each nucleus of chlorine “feel” going around it? How does this number compare to the number of electrons around the nucleus of the next noble gas? 18, the same. 12. Give, in your own words, an explanation for the fact that the element chlorine at room temperature exists as diatom ...
1. Chlorine will combine with the non
... Sodium chloride, an ionic compound, has a high melting point whereas paraffin wax, a molecular compound, melts easily. Explain why. ...
... Sodium chloride, an ionic compound, has a high melting point whereas paraffin wax, a molecular compound, melts easily. Explain why. ...
Chlorine Chemistry For Water and Waste Treatment
... Chloramines collectively are called COMBINED CHLORINE RESIDUAL and have a much lower bactericidal effectiveness than Free chlorine residual. Total Chlorine Residual - The sum of free and combined chlorine residual equals the TOTAL CHLORINE RESIDUAL. FREE + COMBINED = TOTAL NOTE: Methods are availab ...
... Chloramines collectively are called COMBINED CHLORINE RESIDUAL and have a much lower bactericidal effectiveness than Free chlorine residual. Total Chlorine Residual - The sum of free and combined chlorine residual equals the TOTAL CHLORINE RESIDUAL. FREE + COMBINED = TOTAL NOTE: Methods are availab ...
AP Chemistry
... 8.48 g of a compound containing only C, H and O is completely burned. It gives off 12.42 g of carbon dioxide and 5.08 g of water. What is the mass percentage of each element in this compound? ...
... 8.48 g of a compound containing only C, H and O is completely burned. It gives off 12.42 g of carbon dioxide and 5.08 g of water. What is the mass percentage of each element in this compound? ...
637Lesson15
... • There are two main classes of PSC. • Type 1 PSC are small (<1mm) HNO3 rich particles. These have a mass mixing ratio of about 10 ppbm. • Type II PSC are larger (from 10 mm to about 1 mm) composed primarily of H2O-ice with minor amounts of HNO3 as hydrates. • They can constitute up to 1000 ppbm of ...
... • There are two main classes of PSC. • Type 1 PSC are small (<1mm) HNO3 rich particles. These have a mass mixing ratio of about 10 ppbm. • Type II PSC are larger (from 10 mm to about 1 mm) composed primarily of H2O-ice with minor amounts of HNO3 as hydrates. • They can constitute up to 1000 ppbm of ...
Name________________ Hour____ Chapter 11 Review 1. Name
... c. Is a catalyst used? How do you know? Carbon dioxide No, it would be written above the arrow j. How many total atoms are reacting? 6 d. Name the element in the reaction. Oxygen k. How many total atoms are produced? 6 e. Name the compound on the reactant side. Carbon monoxide l. Which substances ha ...
... c. Is a catalyst used? How do you know? Carbon dioxide No, it would be written above the arrow j. How many total atoms are reacting? 6 d. Name the element in the reaction. Oxygen k. How many total atoms are produced? 6 e. Name the compound on the reactant side. Carbon monoxide l. Which substances ha ...
Compounds of Chlorine
... Dichlorine tetraoxide (Cl2 O4 ) is commonly called chlorine perchlorate as a consequence of its structure (Figure 4c). Dichlorine hexaoxide (Cl2 O6 ) is an unstable red oil that has the ionic structure in the solid state: [ClO2 ]+ [ClO4 ]- . Dichlorine heptoxide (Cl2 O7 ) is a relatively stable oil, ...
... Dichlorine tetraoxide (Cl2 O4 ) is commonly called chlorine perchlorate as a consequence of its structure (Figure 4c). Dichlorine hexaoxide (Cl2 O6 ) is an unstable red oil that has the ionic structure in the solid state: [ClO2 ]+ [ClO4 ]- . Dichlorine heptoxide (Cl2 O7 ) is a relatively stable oil, ...
CHEM1411,chapter 1-2-3 exercises 1. In 1828, the diameter of the
... 19. Calculate the percent composition by mass of carbon in Na2CO3. 20. Commonly used gases in the laboratory are generally obtained from pressurized metal gas cylinders, but for small amounts of occasionally used gases, it is sometimes easier just to prepare them chemically as needed. For example, n ...
... 19. Calculate the percent composition by mass of carbon in Na2CO3. 20. Commonly used gases in the laboratory are generally obtained from pressurized metal gas cylinders, but for small amounts of occasionally used gases, it is sometimes easier just to prepare them chemically as needed. For example, n ...
Chlorine
Chlorine is a chemical element with symbol Cl and atomic number 17. Chlorine is in the halogen group (17) and is the second lightest halogen following fluorine. The element is a yellow-green gas under standard conditions, where it forms diatomic molecules. Chlorine has the highest electron affinity and the third highest electronegativity of all the reactive elements. For this reason, chlorine is a strong oxidizing agent. Free chlorine is rare on Earth, and is usually a result of direct or indirect oxidation by oxygen.The most common compound of chlorine, sodium chloride (common salt), has been known since ancient times. Around 1630, chlorine gas was first synthesized in a chemical reaction, but not recognized as a fundamentally important substance. Characterization of chlorine gas was made in 1774 by Carl Wilhelm Scheele, who supposed it to be an oxide of a new element. In 1809, chemists suggested that the gas might be a pure element, and this was confirmed by Sir Humphry Davy in 1810, who named it from Ancient Greek: χλωρóς (khlôros) ""pale green"".Nearly all chlorine in the Earth's crust occurs as chloride in various ionic compounds, including table salt. It is the second most abundant halogen and 21st most abundant chemical element in Earth's crust. Elemental chlorine is commercially produced from brine by electrolysis. The high oxidizing potential of elemental chlorine led commercially to free chlorine's bleaching and disinfectant uses, as well as its many uses of an essential reagent in the chemical industry. Chlorine is used in the manufacture of a wide range of consumer products, about two-thirds of them organic chemicals such as polyvinyl chloride, as well as many intermediates for production of plastics and other end products which do not contain the element. As a common disinfectant, elemental chlorine and chlorine-generating compounds are used more directly in swimming pools to keep them clean and sanitary.In the form of chloride ions, chlorine is necessary to all known species of life. Other types of chlorine compounds are rare in living organisms, and artificially produced chlorinated organics range from inert to toxic. In the upper atmosphere, chlorine-containing organic molecules such as chlorofluorocarbons have been implicated in ozone depletion. Small quantities of elemental chlorine are generated by oxidation of chloride to hypochlorite in neutrophils, as part of the immune response against bacteria. Elemental chlorine at high concentrations is extremely dangerous and poisonous for all living organisms, and was used in World War I as the first gaseous chemical warfare agent.