Mole measure the number of elementary entities of a given substance that are present in a given sample. 3 mole of Cr are in 156 g of the element. The correct option is option B.
The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically, mole and molar mass of chromium can be related as :
number of mole =given mass of chromium÷ molar mass of chromium
Mass of chromium=156 g
Molar mass of 1 mole of chromium= 51.9961 g/mol
Substituting the given values we get,
number of mole =156 g ÷ 51.9961 g/mol
number of mole= 3
Therefore, the correct option is option B. 3 mole of Cr are in 156 g of the element.
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You are given the number of grams of Chromium which is 156 grams. The molar mass of chromium is 52 grams per mole. Divide 156 grams to 52 grams per mole of Chromium and you will get 3 moles of Chromium. The answer is letter B.
The pressure of the gas will become double when its Kelvin temperature becomes its initial value.
Further Explanation:
Ideal gas equation:
Ideal gas is just a theoretical concept and practically no gas can act as ideal. It can be considered as group of random moving particles having perfectly elastic collisions between them.
Ideal gas equation for one mole of gas is mentioned below.
PV = RT …… (1)
Here,
P is the gas pressure.
V is the gas volume.
T is the absolute temperature of gas.
R is the universal gas constant.
Standard conditions refer to state when pressure of gas is 1 atm and its temperature is 273 K.
Consider P’ and T’ to be new pressure and temperature respectively while all other terms in ideal gas equation remains constant. Equation (1) then modifies as follows:
P’V = RT’ …… (2)
Since new pressure is doubled, P’ becomes 2P. Equation (2) becomes,
(2P)V = RT’ …… (3)
Dividing equation (3) by equation (1), we get:
…… (4)
Solving for T’,
Therefore pressure is doubled when temperature becomes twice its initial value.
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Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Ideal gas equation
Keywords: ideal gas equation, R, T, P, V, 2P, 2T, pressure, volume, universal gas constant, P’, T’, standard conditions.
(B) A catalyst reduces the ∆H of a reaction and hence the temperature needed to produce products.
(C) A catalyst reduces the activation energy for a reaction and increases the rate of a reaction.
(D) A catalyst increases the equilibrium constant and final product concentrations
1. molecules rearrange and form new molecules
2. simultaneous decomposition and synthesis
3. bonds broken and elements released
4. molecules formed from components
Answer:
Synthesis - 4
reversible- 2
exchange- 1
decomposition-3
Explanation:
In synthesis reaction two or more components combines to form a single product. example 2H2+O2⇒2H2O
In reversible reaction two reactants combine to form two products . The products then reacts and forms back the reactants. example N2 +3H2 ⇒2NH3
In exchange reaction there is an alternation of ions of reactants to form new products. AB+CD ⇒AC + BD
In decomposition reaction, molecules of a compound break down by the action of heat or light or catalyst. example CaCO3 ⇒CaO +CO2
Synthesis involves creating new molecules from components, while Decomposition involves breaking molecules down into their separate elements. Exchange is when molecules rearrange and form new molecules, and Reversible reactions can go forward or backwards.
In chemistry, various types of chemical reactions have different characteristics. Here's how they match with the provided definitions:
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B. nuclear fission
C. nuclear fusion
D. combustion