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2 years ago

Which of the following is most likely to yield the fossils that help scientists reconstruct the Earth's biological history?

Chemistry

2 answers:

Orlov [11]2 years ago

5 0

A. Sedimentary rock. This is because sedimentary rock contains sediments and sometimes some fossils.

NARA [144]2 years ago

4 0

The answer is: A. Sedimentary Rock

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How many metals are on the periodic table?

sergey [27]

There are 91 metals on the periodic table.

7 0

2 years ago

Read 2 more answers

A student reacted NiS2 (MM = 122.83 g/mol) with O2 (MM=32.00 g/mol) to make SO2 (MM=64.07 g/mol) according to this balanced equa

Mice21 [21]

Answer:

Theoretical yield of SO₂ is 1.56 × 10² g

Explanation:

Given data:

Mass of NiS₂ = 1.50 ×10² g

Mass of O₂ = 2.420 ×10² g

Theoretical yield of SO₂ = ?

Solution:

Chemical equation:

2NiS₂ + 5O₂ → 2NiO + 4SO₂

Moles of NiS₂:

Number of moles = mass/ molar mass

Number of moles = 1.50 ×10² g / 122.83 g/mol

Number of moles = 1.22 mol

Moles of O₂:

Number of moles = mass/ molar mass

Number of moles = 2.420 ×10² g / 32 g/mol

Number of moles = 7.56 mol

Now we compare the moles of SO₂ with NiS₂ and O₂.

NiS₂ : SO₂

2 : 4

1.22 : 4/2×1.22 = 2.44

O₂ : SO₂

5 : 4

7.56 : 4/5×7.56 =6.05

Moles of SO₂ produced by NiS₂ are less it will limiting reactant.

Mass of SO₂ = moles × molar mass

Mass of SO₂ = 2.44 mol × 64.07 g/mol

Mass of SO₂ = 156.33 g

So theoretical yield of SO₂ is 1.56 × 10² g

4 0

2 years ago

a household’s voltage is 120 volts, what is the power rating of a light bulb with 0.5 amps of current flowing through it?

xenn [34]

Your answer should be 110 volts

3 0

2 years ago

What is the expensive property of a substance

olya-2409 [2.1K]

is there any choices?

6 0

2 years ago

Consider 2 Al + 6 HCl → 2 AlCl3 + 3 H2 , the reaction of Al with HCl to produce hydrogen gas. What is the pressure of H2 if the

Margaret [11]

Answer : The pressure of hydrogen gas is 8.96 atm.

Explanation :

The given balanced chemical reaction is:

$2Al+6HCl\rightarrow 2AlCl_3+3H_2$

From the balanced chemical reaction we conclude that,

As, 2 moles of Al react to give 3 moles of $H_2$ gas

So, 4.50 moles of Al react to give $\frac{3}{2}\times 4.50=6.75$ moles of $H_2$ gas

Now we have to calculate the moles of $H_2$ gas when percent yield is 75.4.

$\text{The moles of }H_2=75.4\% \times 6.75=\frac{75.4}{100}\times 6.75=5.09moles$

Now we have to calculate the pressure of $H_2$ gas.

Using ideal gas equation :

PV = nRT

where,

P = Pressure of hydrogen gas = ?

V = Volume of the hydrogen gas = 14.0 L

n = number of moles of hydrogen gas = 5.09 moles

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of hydrogen gas = 300 K

Putting values in above equation, we get:

$P\times 14.0L=5.09mol\times 0.0821L.atm/mol.K\times 300K\\\\P=8.96atm$

Therefore, the pressure of hydrogen gas is 8.96 atm.

3 0

2 years ago