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2 years ago

Among the alkaline earth metals in Group 2A/A, which is more reactive - beryllium (element 4) or strontium (element 38)?

Chemistry

1 answer:

umka2103 [35]2 years ago

5 0

Answer:

Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A.

Explanation:

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Which of the following best summarizes the ideal gas law?

8090 [49]

Answer:

Option C. PV = nRT

Explanation:

The ideal gas gas equation gives the relationship between pressure, volume, number mole a gas and temperature of gas.

Mathematically, the ideal gas equation is given as:

PV = nRT

Where:

P is the pressure measured in atmosphere (atm).

V is the volume measured in litres(L) or cubic decimetre (dm³).

n is the number of mole of gas.

R is the gas constant (0.0821atm.L/Kmol)

T is temperature measured in Kelvin (K).

4 0

3 years ago

A 17.11 gram sample of an organic compound containing only C, H, and O is analyzed by combustion analysis and 21.71 g CO2 and 5.

Andru [333]

Answer: The empirical formula and the molecular formula of the organic compound is $CHO$ and $C_4H_4O_4$ respectively.

Explanation:

The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:

$C_xH_yO_z+O_2\rightarrow CO_2+H_2O$

where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.

We are given:

Mass of $CO_2$ = 21.71 g

Mass of $H_2O$ = 5.926 g

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 21.71 g of carbon dioxide, = $\frac{12}{44}\times 21.71=5.921g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18g of water, 2 g of hydrogen is contained.

So, in 5.926 g of water, = $\frac{2}{18}\times 5.926=0.658g$ of hydrogen will be contained.

Mass of oxygen in the compound = (17.11) - (5.921+0.658) = 10.53 g

Mass of C = 5.921 g

Mass of H = 0.658 g

Mass of O = 10.53 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{5.921g}{12g/mole}=0.493moles$

Moles of H= $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.658g}{1g/mole}=0.658moles$

Mass of O= $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{10.53g}{16g/mole}=0.658moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{0.493}{0.493}=1$

For H = $\frac{0.658}{0.493}=1$

For O= $\frac{0.658}{0.493}=1$

The ratio of C : H: O = 1: 1: 1

Hence the empirical formula is $CHO$ .

empirical mass of CHO = 12(1) + 1(1) + 1 (16) = 29

Molecular mass = 104.1 g/mol

$n=\frac{\text {Molecular mass}}{\text {Equivalent mass}}=\frac{104.1}{29}=4$

Thus molecular formula = $n\times {\text {Empirical formula}}=4\times CHO=C_4H_4O_4$

6 0

2 years ago

When a cube of manganese oxide was added to a solution of hydrogen peroxide, water and oxygen were produced. Manganese oxide was

FromTheMoon [43]

Smashing the cube into pieces

Explanation:

Smashing the cube into pieces will most likely increase the reaction rate between the manganese oxide and hydrogen peroxide.

The rate of a chemical reaction is a measure of the speed of a chemical reaction.

Some factors that affects the rate of chemical reaction are:

Nature of the reactants
Concentration of the reactants or pressure if gases.
Temperature
Presence of a catalyst.
Sunlight(some reactions are light catalyzed)

The nature of reactants implies the physical state of matter, bond type or surface area exposed of reacting species.
The surface area exposed is directly proportional to the reaction rate.
Breaking the cubes into smaller pieces exposes more surface area to the chemical action and the reaction rate increases.

Learn more:

Activation energy brainly.com/question/3930233

#learnwithBrainly

6 0

3 years ago

Read 2 more answers

7. Which of the following pairs of atoms are isotopes? a) C14 & N14 b) U235 & U238 c) C12 & C12 d) C12 & N14 e)

Ede4ka [16]

Answer:

b) U235 & U238

Explanation:

Isotopes are the variants of a element which differ in the number of neutrons , and in the nucleon number consequently . All isotopes of the element have same number of the protons but different numbers of the neutrons.

(a) Isotopes are the properties of an element. Hence, not isotopes.

(b) Uranium is the element which exists in mass number 235 and 238 and they are the isotopes of the uranium element. Hence, they are isotopes.

(d) Isotopes are the properties of an element. Hence, not isotopes.

3 0

3 years ago

The boiling point of chlorine (Cl2) is 171.6 K. Which of the

jeka94

Answer:

The boiling point of iodine is 363.7°F / 184.3°C

7 0

2 years ago