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3 years ago

Which of these is a compound? A. Steel B.Sugar C.Air D.Nitrogen

Chemistry

2 answers:

hjlf3 years ago

8 0

Sugar is a compound made of carbon, hydrogen and oxygen.

vlada-n [284]3 years ago

4 0

Answer: The correct option is B.

Explanation:

An element is the simplest substance which cannot be divided further and is made up from only one type of atoms. Example: oxygen, nitrogen etc.

A compound is defined as a substance which is formed by the combination of two or more elements in a fixed ratio. Example: $CO_2,H_2O$ etc.

A mixture is formed by the combination of elements or compounds in a non-uniform ratio. Example: Salt in water

Option A: Steel is a alloy of 96% iron, carbon and many other elements. This is a homogeneous mixture of more than 2 elements. Hence, it is considered as a mixture because elements are not present in a fixed ratio.

Option B: Formula for sugar is $C_{12}H_{22}O_{11}$ . This is a compound made from the elements: Carbon, Hydrogen and Oxygen in a fixed ratio of 12 : 22: 11. Hence, it is considered as a compound.

Option C: Air is a mixture of many gases. Gases present in air are nitrogen, oxygen, argon , carbon dioxide etc. These gases are not present in fixed ratio.

Option D: Nitrogen is the simplest unit of substance. It is considered as an element.

Hence, the correct option is B.

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Need help !!!!! ASAP

Ksivusya [100]

<h2>Hello!</h2>

The answer is:

We have that there were produced 0.120 moles of $CO_{2}$

$n=0.120mol$

We are asked to calculate the number of moles of the given gas, also, we are given the volume, the temperature and the pressure of the gas, we can calculate the approximate volume using The Ideal Gas Law.

The Ideal Gas Law is based on Boyle's Law, Gay-Lussac's Law, Charles's Law, and Avogadro's Law, and it's described by the following equation:

$PV=nRT$

Where,

P is the pressure of the gas.

V is the volume of the gas.

n is the number of moles of the gas.

T is the absolute temperature of the gas (Kelvin).

R is the ideal gas constant (to work with pressure in mmHg), which is equal to:

$R=62.363\frac{mmHg.L}{mol.K}$

We must remember that the The Ideal Gas Law equation works with absolute temperatures (K), so, if we are given relative temperatures such as Celsius degrees or Fahrenheit degrees, we need to convert it to Kelvin before we proceed to work with the equation.

We can convert from Celsius degrees to Kelvin using the following formula:

$Temperature(K)=Temperature(C\°) + 273K$

So, we are given the following information:

$Pressure=760mmHg\\Volume=2.965L\\Temperature=25.5C\°=25.5+273K=298.5K$

Now, isolating the number of moles, and substituting the given information, we have:

$PV=nRT$

$n=\frac{PV}{RT}$

$n=\frac{760mmHg*2.965L}{62.363\frac{mmHg.L}{mol.K}*298.5K}$

$n=\frac{760mmHg*2.965L}{62.363\frac{mmHg.L}{mol.K}*298.5K}\\\\n=\frac{2242mmHg.L}{18615.355\frac{mmHg.L}{mol.}}\\\\n=0.120mole$

Hence, we have that there were produced 0.120 moles of $CO_{2}$

$n=0.120mol$

Have a nice day!

7 0

3 years ago

Use the limiting reagent to determine how many grams of Cu(OH)2 should precipitate out in the reaction - CuSo4(aq) + 2NaOH(aq) -

Elis [28]

I think there is a lack of information in the given problem above such as the grams of copper sulfate and sodium hydroxide that was used in the experiment. Kindly resubmit the question with the complete details so that we can help you. Thank you.

7 0

2 years ago

Read 2 more answers

Calculate the standard enthalpy change for the reaction at 25 ∘ C. Standard enthalpy of formation values can be found in this li

meriva

Answer:

The standard enthalpy change for the reaction at $25^{0}\textrm{C}$ is -2043.999kJ

Explanation:

Standard enthalpy change ( $\Delta H_{rxn}^{0}$ ) for the given reaction is expressed as:

$\Delta H_{rxn}^{0}=[3mol\times \Delta H_{f}^{0}(CO_{2})_{g}]+[4mol\times \Delta H_{f}^{0}(H_{2}O)_{g}]-[1mol\times \Delta H_{f}^{0}(C_{3}H_{8})_{g}]-[5mol\times \Delta H_{f}^{0}(O_{2})_{g}]$

Where $\Delta H_{f}^{0}$ refers standard enthalpy of formation

Plug in all the given values from literature in the above equation:

$\Delta H_{rxn}^{0}=[3mol\times (-393.509kJ/mol)]+[4mol\times (-241.818kJ/mol)]-[1mol\times (-103.8kJ/mol)]-[5mol\times (0kJ/mol)]=-2043.999kJ$

4 0

2 years ago

How would a flood be a limitation for synthetic polymers that rely on natural rubber in its production?

Zepler [3.9K]

A flood, if it hits the environment of the natural rubbers, would destroy how the rubber is being produced. to have a large amount of limitation, the flood would destroy a large percentage of rubber trees. This natural rubber is needed to make synthetic polymers. Without the rubber (because of damages to it's ecosystem through the flood), there would be a limited supply, and a substancial drop on synthetic polymers.

hope this helps

3 0

3 years ago

Read 2 more answers

why did mendeleev leave blank spaces on his periodic table? did later discoveries justify his predictions?

schepotkina [342]

Answer:

mendeleev left a space

Explanation:

so the periodic table can be organize

7 0

2 years ago