Chemistry Unit 7 Test Questions – Flashcards
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A substance that enters into a chemical reaction is called a
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reactant
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in a reaction in which hydrogen reacts with oxygen to produce water which substance are the reactants
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both hydrogen and oxygen
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which is not an example of a chemical change
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cutting paper
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in a chemical equation that symbol that takes the place of the words react with is a
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plus sign
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in a chemical equation the symbol that take place of the word yields is an
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arrow
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when oxygen is available sulfur dioxide is produce from the burning of sulfur. how is the best way to represent this reaction
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sulfur + oxygen-> sulfur dioxide
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the world equation magnesium reacts with chlorine to produce magnesium chloride would be best represented by which of the following formula equations
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Mg + Cl2 -> MgCl2
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which of the following is true of a balanced equation
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the number of atoms of each element remains the same
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in a chemical reaction what is the relationship between the total mass of the reactants and the total mass of the products
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they must be equal
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in a chemical equation the number of molecules of a given substance is indicated by a
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coefficient
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how many atoms of oxygen are represented in 2Ca(O3)2
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12
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in balancing a chemical equation which of the following are you supposed to do
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write coefficients
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the symbol (s) written after a formula in a chemical equation stands for
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solid
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which of the following symbols means a substance is in water solution
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(aq)
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what is the general form for a single replacement reaction
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A +BX-> AX +B
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what is the general form for a double replacement reaction
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AX + BY-> AY+BX
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what kind of reaction is represented by the equation C2Cl4+ Cl2-> C2Cl6
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synthesis
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a chemical reactions has not occurred if the products have
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the same chemical properties as the reactants
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which observation does not indicate that a chemical reaction has occurred
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change in total mass of substances
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a solid produced by a chemical reaction in solution that separates from the solution is called
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a precipitate
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after the correct formula for a reactant in an equation has been written the
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formula should not be changed
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in writing an equation that produces hydrogen gas the correct representation of hydrogen gas is
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H2
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to balance a chemical equation it may be necessary to adjust the
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coefficients
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according to the law of conservation of mass the total mass of the reacting substances is
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always equal to the total mass of the products
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for the formula 2Mg ->2Mgo the word equation would begin
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magnesium plus oxygen
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after the first steps in writing an equation the equation is balanced by
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adjusting coefficients to the smallest whole number ratio
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the reaction 2Mg+ O2-> 2MgO is a
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synthesis reaction
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Mg+2HCL -> H2 + MgCl2 is an
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single replacement reaction
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the reaction 2HgO-> 2Hg + O2 is an
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decomposition reaction
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Pb(NO3)2 + 2KI -> PbI2 + 2KNO3
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double replacement reaction
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2KClO3-> 2KCl + 3O2
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decomposition reaction
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In one type synthesis reaction an element combines with oxygen to yield a
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oxide
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when a binary compound decomposed what is produced
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two elements
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in the equation 2Al + 3Fe(NO3)2 -> 3FE+ 2Al(NO3)3 iron has been replaced by
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aluminum
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in a double replacement reaction hydrogen chloride and sodium hydroxide react to produce sodium chloride another product is
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water
