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1 | |
Examine the chemical equation below.
nitrogen gas + oxygen gas → nitrogen dioxide gas
Reading from left to right, which is the correct classification of the chemicals in this equation? |
| | A) | product, product, reactant, |
| | B) | reactant, reactant, product |
| | C) | reactant, product, product |
| | D) | product, reactant, product |
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2 | |
Paul reads a chemical equation as "Diammonia produces nitrogen gas and hydrogen gas". The equation is:
2NH3(g)→N2(g)+3H2(g)
How should Paul's error be corrected?
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| | A) | Instead of "diammonia", Paul should have said "ammonia". |
| | B) | Instead of "diammonia", Paul should have said "nitrogen trihydride". |
| | C) | Instead of "hydrogen gas", Paul should have said "dihydride". |
| | D) | Instead of "hydrogen gas", Paul should have said, "trihydrogen". |
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3 | |
What is the correct chemical formula of the first product in the following reaction:
calcium metal + hydrochloric acid → calcium chloride + hydrogen gas |
| | A) | CaCl |
| | B) | 2CaCl |
| | C) | 2CaCl2 |
| | D) | CaCl2 |
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4 | |
What are the coefficients of the reactants and products, in the order listed, when the following skeleton chemical equation is balanced?
K(s) + H2O(l)→KOH(aq) +H2(g)
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| | A) | 1, 1, 1, 1 |
| | B) | 2, 2, 2, 2 |
| | C) | 2, 2, 2, 1 |
| | D) | 1, 2, 2, 2 |
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5 | |
What is the best description of this chemical equation?
H2(g)+Cl2(g) →2HCl(g) |
| | A) | balanced, because the number of atoms of each element is the same on the left side and the right side of the chemical equation |
| | B) | balanced, because the total number of molecules stays the same on the left side and the right side of the chemical equation |
| | C) | unbalanced, because there are two reactants and only one product |
| | D) | unbalanced, because the reactants do not have any coefficients |
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6 | |
Tania pours hydrochloric acid over a piece of magnesium ribbon in an open beaker. She notices that heat is released, along with bubbles of gas. What is the best description of Tania's experimental setup? |
| | A) | an open system, so observations will support the law of conservation of mass |
| | B) | an open system, so observations will not support the law of conservation of mass |
| | C) | a closed system, so observations will support the law of conservation of mass |
| | D) | a closed system, so observations will not support the law of conservation of mass |
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7 | |
An acid-base neutralization reaction is represented by this chemical equation:
HCl(aq) + KOH(aq) → KCl(aq + H2O(l) + energy
What is the best description of the reaction? |
| | A) | endothermic, causing the surroundings to warm up |
| | B) | endothermic, causing the surroundings to cool down |
| | C) | exothermic, causing the surroundings to warm up |
| | D) | exothermic, causing the surroundings to cool down |
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