Chemistry Questions
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Calcium carbonate, CaCO₃, reacts to form calcium oxide, CaO, and carbon dioxide, CO₂. What type of reaction is this?a. synthesisb. replacementc. combustiond. decomposition
The activity series helps to predicta. the amount of product formed by a chemical reactionb. whether or not a specific chemical reaction is possiblec. the coefficients needed to balance a chemical equationd. the amount of energy needed to start a chemical reaction
In which type of reaction do two or more compounds react to form one product?a. synthesisb. decompositionc. combustiond. single-displacement
What type of chemical reaction is represented by the following word equation?Iron + Oxygen → Iron(II) oxidea. synthesisb. replacementc. combustiond. double-replacement
How many mole ratios can be correctly obtained from the chemical equation 2Al₂O₃→4Al+3O₂?a. 3b. 4c. 6d. 8
The coefficients in a chemical equation represent the a. masses, in grams, of all reactants and productsb. relative numbers of moles of reactants and productsc. number of atoms in each compound in a reactiond. number of valence electrons involved in the reaction
What type of chemical reaction does the following chemical equation represent?2HCl(aq)+Cr(s)→H₂(g)+CrCl₂(aq)a. compositionb. single-displacementc. decompositiond. double-displacement
In the equation 2Al₂O₃→4Al+3O₂, what is the mole ratio of aluminum to oxygen?a. 10:6b. 3:4c. 2:3d. 4:3
The actual yield of a chemical reaction is generallya. less than the theoretical yieldb. greater than the theoretical yieldc. equal to the percentage yieldd. greater than the percentage yield
Actual yield must be determined by a. experimentsb. calculationsc. theoretical yieldd. estimation
To determine the limiting reactant in a chemical reaction involving known masses of the two reactants, which of the following would be most useful?a. determining the massesb. determining the molar masses of the productsc. calculating bond energiesd. calculating the mass of a single product formed from each reactant
Which of the following equations represents the balanced equation for the reaction of iron and oxygen?a. 2Fe+O₂→Fe₂O₃b. Fe+3O₂→Fe₂O₃c. 4Fe+3O₂→2Fe₂O₃d. 3Fe
Fewer steps are required to solve stoichiometry problems whena. the reactant is given in grams and the product is sought in gramsb. the reactant is given in moles and the product is sought in molesc. the reactant is given in grams and the product is sought in litersd. the reactant is given in liters and the product is sought in number of atoms
In a single-displacement reaction, an element in the activity series most likely can replace any elementa. above it on the listb. in the same groupc. below it on the listd. in any other group
If calcium is listed above magnesium in the activity series, and magnesium is listed above zinc, which of the following reactions is possible?a. Ca+MgCl₂b. Zn+MgCl₂c. Zn+CaCl₂d. Mg+CaCl₂
A balanced chemical equation allows one to determine the a. mole ratio of any two substances in the reactionb. energy released in the reactionc. electron configuration of all elements in the reactiond. mechanism involved in the reaction
Which of the following is true regarding single-displacement reactions?a. Only one product is formedb. There is only one reagentc. It requires oxygend. One element replaces another in a compound.
Which of the following is true regarding double-displacement reactions?a. Two products are formedb. The ions of the two reactants must be exchanged.c. A precipitate may formd. All of the above
What is the correct formula for the compound made of magnesium and nitrogen?a. Mg₂N₃b. Mg₃N₂c. MgN₂d. MgN
What follows an element's symbol in a chemical formula to indicate the number of atoms of that element in one molecule of the compound?a. charge signb. superscripted numberc. number in parenthesesd. subscripted number