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3 years ago

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A sample of chemical x is found to contain 5.0 grams of oxygen, 10.0 grams of carbon, and 20.0 grams of nitrogen. The law of def

inite proportion would predict that a 61 gram sample of chemical x should contain how many grams of carbon? 17 grams

1 answer:

Minchanka [31]3 years ago

7 0

A simple proportion,
$10 \div 35 = x \div 61$
$61 \times 10 = 610$
$610 \div 35 = 17.42857$
so x= 17.43~

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Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolat

ad-work [718]

Answer:

The correct answer is 0.00582 grams.

Explanation:

In order to solve the question, let us consider the vapor pressure of H2O, as hydrogen gas is collected over water, therefore, we have to consider the vapor pressure of water in the given case. Let us assume that the pressure is 760 torr or 1 atm.

It is known that the vapor pressure of water at 40 degree C is 53.365 torr (Based on the data).

Therefore, the pressure of H2 will be,

P = 760-55.365 = 704.635 torr or 704.635/760 = 0.9272 atm

The volume of the hydrogen gas collected in the tube is 80 ml or 0.08 L

Temperature in Kelvin will be 40+273 = 313 K

To calculate the moles of hydrogen (H2) gas, there is a need to use the ideal gas equation, that is, PV= nRT, in this R is the gas constant, whose value is 0.0821 L atm/molK, and n is the moles of the gas.

By inserting the values in the equation we get:

PV = nRT

n = PV/RT = 0.9272 *0.08 / 0.0821 * 313

n = 0.00289 moles

The mass of H2 will be moles * molar mass = 0.00289 * 2.016

= 0.00582 grams.

7 0

3 years ago

The formation of a gas in a chemical reaction, due to ions changing places, often indicates that the reaction is which type?

Gelneren [198K]

A single-displacement reaction, also known as asingle-replacement reaction, is a type of chemicalreaction<span> where an element reacts with a compound and takes the place of another element in that compound. This type of </span>reaction<span> is typically pictured like this: Here, A replaces B in the compound BC.</span>

6 0

3 years ago

Read 2 more answers

In an experiment, 4.14 g of phosphorus combined with chlorine to produce 27.8 g of a white solid compound. what is the empirical

Umnica [9.8K]

Grams of Phosphorus = 4.14 grams
Grams of white compound = 27.8 grams
Grams of Chlorine would be = 27.8 - 4.14 = 23.66 grams
Calculating moles which would be grams / molar mass
Molar mass of P = 30.97 grams / moles; Molar mass of Cl = 35.45 grams / moles
Moles of Phosphorus = 4.14 grams / 30.97 grams / moles = 0.1337 moles
Moles of Chlorine = 23.66 grams / 35.45 grams / moles = 0.6674 moles
Calculating the ratios by dividing with the small entity
P = 0.1337 moles / 0.1337 moles = 1
Cl = 0.6674 moles / 0.1337 moles = 5
So the empirical formula would be PCl5

3 0

3 years ago

Antarctica, almost completely covered in ice, has an area

Marysya12 [62]

<u>Answer:</u> The mass of ice is $2.39\times 10^{22}g$

<u>Explanation:</u>

We are given:

Area of Antarctica = $5,500,000mi^2=5,500,000\times 2.59\times 10^{10}=142.45\times 10^{15}cm^2$ (Conversion factor: $1mi^2=2.59\times 10^{10}cm^2$ )

Height of Antarctica with ice = 7500 ft.

Height of Antarctica without ice = 1500 ft.

Height of ice = 7500 - 1500 = 6000 ft = $182.88\times 10^3cm$ (Conversion factor: 1 ft = 30.48 cm)

To calculate mass of ice, we use the equation:

$\text{Density of a substance}=\frac{\text{Mass of a substance}}{\text{Volume of a substance}}$

We are given:

Density of ice = $0.917g/cm^3$

Volume of ice = Area × Height of ice = $142.45\times 10^{15}cm^2\times 182.88\times 10^3cm=26051.26\times 10^{18}cm^3$

Putting values in above equation, we get:

$0.917g/cm^3=\frac{\text{Mass of ice}}{26051.26\times 10^{18}cm^3}\\\\\text{Mass of ice}=(0.917g/cm^3\times 26051.26\times 10^{18}cm^3=2.39\times 10^{22}g$

Hence, the mass of ice is $2.39\times 10^{22}g$

5 0

3 years ago

What is the effect of high activation energy on a chemical reaction?

alex41 [277]

<h3><u>Answer;</u></h3>

It makes the reaction harder to start

<h3><u>Explanation</u>;</h3>

<em><u>Activation energy is minimum amount of energy that is required for a reaction to start. Activation energy determines the rate of a chemical reaction such that the higher the activation energy, the lower the rate of chemical reaction and vice versa.</u></em>
The source of activation energy needed to push chemical reactions forward is obtained from the surroundings. Catalyst speed up chemical reaction by lowering the activation energy. Therefore, catalysis is the increase in the rate of a chemical reaction by lowering its activation energy.

4 0

3 years ago