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3 years ago

Boron has an atomic mass of 10.811. What does this mean?

Chemistry

1 answer:

icang [17]3 years ago

6 0

Answer:

Knowing that boron has an atomic mass of 10,811 means that all boron isotopes on average weigh 10,811 u.

Explanation:

The atomic mass of an atom is the mass of the atom measured in u (unified atomic mass unit), although we can also express it as Da (Dalton's unit)

Atomic mass refers to the average mass that all isotopes of that element have.

When we speak of isotopes we are referring to the element itself but with a different number of neutrons, which makes it modify its mass number.

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sleet_krkn [62]

Answer:

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3 years ago

In 1953, who devopled the model that is shown below

PilotLPTM [1.2K]

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3 years ago

What does the symbol "E3" represent?

Anna71 [15]

Answer:

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3 years ago

Read 2 more answers

By titration, it is found that 31.7 mL of 0.145 M NaOH(aq) is needed to neutralize 25.0 mL of HCl(aq). Calculate the concentrati

arlik [135]

Answer:

0.184 M

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

HCl + NaOH —> NaCl + H2O

From the balanced equation above, the following data were obtained:

Mole ratio of the acid, HCl (nA) = 1

Mole ratio of the base, NaOH (nB) = 1

Next, the data obtained from the question. This includes:

Volume of the base, NaOH (Vb) = 31.7 mL Molarity of the base, NaOH (Mb) = 0.145 M

Volume of the acid, HCl (Va) = 25.0 mL

Molarity of the acid, HCl (Ma) =?

Finally, we shall determine the molarity of the acid (HCl) as shown below:

MaVa /MbVb = nA/nB

Ma × 25 / 0.145 × 31.7 = 1

Cross multiply

Ma × 25 = 0.145 × 31.7

Ma × 25 = 4.5965

Divide both side by 25

Ma = 4.5965 / 25

Ma = 0.184 M

Therefore, the molarity of the acid (HCl) is 0.184 M

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3 years ago

Calculate the number of pounds of CO2CO2 released into the atmosphere when a 22.0 gallon22.0 gallon tank of gasoline is burned i

Gnesinka [82]

Answer:

391.28771 pounds of carbon-dioxide was released into the atmosphere when 22.0 gallon tank of gasoline is burned in an automobile engine.

Explanation:

Density of the gasoline ,d= 0.692 g/mL

Volume of gasoline in an tanks,V = 22.0 gallons = 83,279.02 mL

Let mass of the gasoline be M

$Density= \frac{Mass}{Volume}$

M = V × d = 83,279.02 mL × 0.692 g/mL=57,629.081 g

Given that gasoline is primarily octane.

$2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O$

Mass of octane burnt in the tank = M = 57,629.081 g

Moles of octane = $\frac{57,629.081 g}{114.08g/mol}=505.1637 mol$

According to reaction, 2 moles of octane gives 16 moles of carbon-dioxide.

Then 505.1637 mol of octane will give:

$\frac{16}{2}\times 505.1637 mol=4,041.3100 mol$ of carbon-dioxide

Mass of 4,041.3100 mol of carbon-dioxide:

4,041.3100 mol × 44.01 g/mol = 177,858.05 g

Mass of carbon-dioxide produced in pounds = 391.28771 pounds

391.28771 pounds of carbon-dioxide was released into the atmosphere when 22.0 gallon tank of gasoline is burned in an automobile engine.

3 0

3 years ago