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Inessa [10]
3 years ago
15

In which era did the first fish appear?

Chemistry
1 answer:
VARVARA [1.3K]3 years ago
5 0
C Because Mesozoic Is An Era The First Fish Seen
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Is reacts with acid a chemical or physical property? (WORTH 30 Points.)
Alborosie

Answer:

Metals in general have they chemical property of reacting with an acid. Zinc reacts with hydrochloric acid to produce hydrogen gas. This is a chemical property. Chemical change results in one or more substances of entirely different composition from the original substances.

3 0
3 years ago
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How many liters of oxygen gas can react with 84.0 grams of lithium metal at standard temperature and pressure? Show all of the w
ddd [48]
From the equation:
4mol Li react with 1 mol O2
Molar mass Li = 7g/mol
mol in 84g Li = 84/7 = 12 mol Li
From the equation - 12 mol Li will react with 3 mol O2

At STP 1 mol O2 has volume = 22.4L
<span> At STP 3 mol O2 has volume = 3*22.4 = 67.2L O2 gas will react. </span>
5 0
3 years ago
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Based upon the mass of baking soda (NaHCO3) and using an excess of HCl in this experiment, you will 1) determine the mass of CO2
weqwewe [10]

Equation of reaction

NaHCO3 +  HCl  --------->  NaCl  +  H2O  +  CO2(g)

1)The mass(actual yield) of CO2 can be gotten by isolating it from other products and getting its mass.

Assume 1.0g of CO2 was gotten as a product of the experiment

2) For the theoretical yield

The mass of NaHCO3 was not stated, but for the purpose of this solution, I would assume 2g of NaHCO3 was used for the experiment. You can substitute any parameter by following the steps I follow

Number of mole of NaHCO3 = Mass of NaHCO3/ Molar Mass of NaHCO3

Number of mole of NaHCO3 = 2/84.01 = 0.0238 moles

1 mole of NaHCO3 yielded 1 mole of CO2

0.0238 moles of NaHCO3 will yield 0.0238 moles of CO2

Mass of CO2 = Number of moles * Molar Mass

Mass of CO2 = 0.0238 * 44 = 1.0472g

Theoretical yield of CO2 = 1.0472 grams

3) Percentage yield of CO2 = Actual yield/Theoretical yield *100%

Percentage yield of CO2 = 1.0/1.0472 *100

Percentage yield of CO2 = 95.49%

8 0
3 years ago
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Which statement regarding this equation is TRUE?
noname [10]

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iron (III) oxide is a gas

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2 years ago
Which of these hypotheses cannot be tested?
SVEN [57.7K]

Cooks should use sea salt in recipes instead of regular table salt.

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3 years ago
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