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3 years ago

Which of the following materials is a substance. air gasoline stainless steel or silver

2 answers:

8 0

Substances are matter that has uniform and constant composition: same number and kind of atoms bonded in the same way.The substances are compounds or elements.From the options given, only silver is a substance, because it is an element, and all silver materials have only silver atoms. Air is a mixture of different gases,which may varies in composition; gasoline is a mixture of liquids which may change in composition; steel is an alloy (a mixture of compounds and elements) which varies in composition. So, the answer is Silver.

ioda3 years ago

8 0

Answer:

the answer is silver ;)

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Someone plz help me :(

sleet_krkn [62]

Explanation:

I mainly think its c. from my point of view because as yoy can see they showed observations and explained certain information and they didnt conclude it as it's TRUE they said theories meaning its and Idea and something that is not fully proven happend.

6 0

3 years ago

Hydrogen gas (a potential future fuel) can be formed by the reaction of methane with water according to the following equation:

rusak2 [61]

Answer:

60.42% is the percent yield of the reaction.

Explanation:

Moles of methane gas at 734 Torr and a temperature of 25 °C.

Volume of methane gas = V = 26.0 L

Pressure of the methane gas = P = 734 Torr = 0.9542 atm

Temperature of the methane gas = T = 25 °C = 298.15 K

Moles of methane gas = n

$PV=nRT$

$n=\frac{PV}{RT}=\frac{0.9542 atm\times 26.0L}{0.0821 atm L/mol K\times 298.15 K}=1.0135 mol$

Moles of water vapors at 700 Torr and a temperature of 125 °C.

Volume of water vapor = V' = 23.0 L

Pressure of water vapor = P' = 700 Torr = 0.9100 atm

Temperature of water vapor = T' = 125 °C = 398.15 K

Moles of water vapor gas = n'

$P'V'=n'RT'$

$n'=\frac{PV}{RT}=\frac{0.9100 atm\times 23.0L}{0.0821 atm L/mol K\times 398.15 K}=0.6402 mol$

$CH_4(g)+H_2O(g)\rightarrow CO(g)+3H_2(g)$

According to reaction , 1 mol of methane reacts with 1 mol of water vapor. As we can see that moles of water vapors are in lessor amount which means it is a limiting reagent and formation of hydrogen gas will depend upon moles of water vapors.

According to reaction 1 mol of water vapor gives 3 moles of hydrogen gas.

Then 0.6402 moles of water vapor will give:

$\frac{3}{1}\times 0.6402 mol=1.9208 mol$ of hydrogen gas

Moles of hydrogen gas obtained theoretically = 1.9208 mol

The reaction produces 26.0 L of hydrogen gas measured at STP.

At STP, 1 mole of gas occupies 22.4 L of volume.

Then 26 L of volume of gas will be occupied by:

$\frac{1}{22.4 L}\times 26 L= 1.1607 mol$

Moles of hydrogen gas obtained experimentally = 1.1607 mol

Percentage yield of hydrogen gas of the reaction:

$\frac{Experimental}{Theoretical}\times 100$

$\%=\frac{ 1.1607 mol}{1.9208 mol}\times 100=60.42\%$

60.42% is the percent yield of the reaction.

8 0

3 years ago

What is the oxidizing agent in galvanic cell?

ipn [44]

The ion in the cathode that gains electrons

7 0

3 years ago

What kind of non-flowering plant produces seeds instead of spores?

Pie

Answer:

The answer to your question is Ferns

Explanation:

Ferns are called nonflowering plants and produce spores instead of seeds.

6 0

3 years ago

How many milliliters of C5H8 can be made from 366 mL C5H12 ?

zlopas [31]

The number of Ml of C₅H₈ that can be made from 366 ml C₅H₁₂ is 314.7 ml of C₅H₈

calculation

step 1: write the equation for formation of C₅H₈

C₅H₁₂ → C₅H₈ + 2 H₂

Step 2: find the mass of C₅H₁₂

mass = density × volume

= 0.620 g/ml × 366 ml =226.92 g

Step 3: find moles Of C₅H₁₂

moles = mass÷ molar mass

from periodic table the molar mass of C₅H₁₂ = (12 x5) +( 1 x12) = 72 g/mol

moles = 226.92 g÷ 72 g/mol =3.152 moles

Step 4: use the mole ratio to determine the moles of C₅H₈

C₅H₁₂:C₅H₈ is 1:1 from equation above

Therefore the moles of C₅H₈ is also = 3.152 moles

Step 5: find the mass of C₅H₈

mass = moles x molar mass

from periodic table the molar mass of C₅H₈ = (12 x5) +( 1 x8) = 68 g/mol

= 3.152 moles x 68 g/mol = 214.34 g

Step 6: find Ml of C₅H₈

=mass / density

= 214.34 g/0.681 g/ml = 314.7 ml

8 0

3 years ago