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2 years ago

What can you do differently for

Chemistry

1 answer:

drek231 [11]2 years ago

3 0

Answer:

I would say, what helps me is really paying attention in class and asking questions, also making sure you study for upcoming test's and quizzes and completely assingments on time

Explanation:

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Use the molar heat capacity for aluminum from table 1 to calculate the amount of energy needed to raise the temperature of 260.5

Nimfa-mama [501]

Unfortunately, you failed to include the table 1 from which the molar heat capacity of aluminum could have been obtained. However, as a general rule, the heat needed to raise the temperature of a certain substance by certain degrees is calculated through the equation,
H = mcpdT
where H is heat, m is mass, cp is specific heat capacity, and dT is change in temperature. From a reliable source, cp for aluminum is equal to 0.215 cal/g°C. Substituting this to the equation,
H = (260.5 g)(0.215 cal/g°C)(125°C - 0)
H = 7000.94 cal

6 0

3 years ago

Calculate the mass of Na2O that can be produced by the chemical reaction of 4.0 grams of sodium with excess oxygen in the reacti

e-lub [12.9K]

Answer:

The mass of Na₂O that can be produced by the chemical reaction of 4.0 grams of sodium with excess oxygen in the reaction is 5.39 grams.

Explanation:

You know the balanced reaction:

4 NA + O₂ ⟶ 2 Na₂O

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) react and are produced:

Na: 4 moles
O₂: 1 mole
Na₂O: 2 moles

Being:

Na: 23 g/ole
O: 16 g/mole

the molar mass of the compounds participating in the reaction is:

Na: 23 g/mole
O₂: 2*16 g/mole= 32 g/mole
Na₂O: 2*23 g/mole +16 g/mole= 62 g/mole

Then by stoichiometry of the reaction they react and are produced:

Na: 4 moles* 23 g/mole= 92 g
O₂: 1 mole*32 g/mole= 32 g
Na₂O: 2 moles* 62 g/mole= 124 g

Then you can apply the following rule of three: if 92 grams of Na produce 124 grams of Na₂O, 4 grams of Na, how much mass of Na₂O does it produce?

$massofNa_{2}O =\frac{4 grams of Na*124 gramsofNa_{2}O }{92 grams of Na}$

mass of Na₂O=5.39 g

<em><u>The mass of Na₂O that can be produced by the chemical reaction of 4.0 grams of sodium with excess oxygen in the reaction is 5.39 grams.</u></em>

8 0

2 years ago

How many grams of potassium nitrate (KNO3) are required to prepare 0.250L of a 0.700 M

CaHeK987 [17]

Answer:

17.78g

Explanation:

m/M = C×V

m/101.102= 0.7× 0.25

m= 101.102×0.7×0.25= 17.78g

6 0

3 years ago

Look at the equation for a displacement reaction below. What lost electrons in the reaction? Give the full name, not the symbols

garri49 [273]

Answer:

Cupric ions

Explanation:

In the single displacement reaction shown, the cupric ions lost two electrons.

Cu²⁺ + 2e⁻ → Cu

The replacement of a metallic ion in solution by a metal atom higher in the activity series than than the metal in solution falls into this category of reactions.

Since Zn higher in the series, it displacements the cupric ions.

5 0

3 years ago

How many significant figures are in these numbers

jenyasd209 [6]

Answer:

Explanation:

a significant number is a non zero number or exponent or a zero between numbers

8 0

2 years ago