Answer:
It’s true
Explanation:
If we account for all reactants and products in a chemical reaction, the total mass will be the same at any point in time in any closed system. ... The Law of Conservation of Mass holds true because naturally occurring elements are very stable at the conditions found on the surface of the Earth.
Answer:
The change of state of wax from solid to liquid and liquid to vapors is a physical change.
Explanation:
Physical Change
The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.
These changes were reversible.
They have same chemical property.
These changes can be observed with naked eye.
Chemical:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
.
These changes occur due to chemical reactions.
These may not be observed with naked eye
Example
When a candle is burned, the both physical and chemical changes occur.
The solid wax is melted into the liquid and than liquid is evaporated into vapor form. It is a physical change because just the state of mater is changed. When vapors of wax are react with oxygen in air and form carbon dioxide and ash it is a chemical change which can not be reversed.
Answer:
1.274.
Explanation:
- Thomas Graham found that, at a constant temperature and pressure the rates of effusion of various gases are inversely proportional to the square root of their masses.
<em>∨ ∝ 1/√M.</em>
where, ∨ is the rate of diffusion of the gas.
M is the molar mass of the gas.
<em>∨₁/∨₂ = √(M₂/M₁)</em>
∨₁ is the rate of effusion of the methane.
∨₂ is the rate of effusion of acetylene gas.
M₁ is the molar mass of methane (M₁ = 16.0 g/mol).
M₂ is the molar mass of acetylene (M₂ = 26.0 g/mol).
<em>∴ The rate of effusion of methane, CH₄, relative to the rate of effusion of acetylene, C₂H₂ = ∨₁/∨₂ = √(M₂/M₁) </em>= √(26.0 g/mol)/(16.0 g/mol) = <em>1.274.</em>
Answer:
The ranking order of the degree of polarity is HF>HCl>HBr>HI
Explanation:
The degree of polarity of a compound depends on the nature electronegative atom that it contains.
Among Fluorine,chlorine,bromine and iodine the electronegativity of fluorine is highest among all the mentioned atoms.
Due to high electronegativity HF is the most polar than HCl,HBr and HI and the HI have least polarity as its atomic structure is large and electronegativity is lower than fluorine,chlorine and bromine.
compressibility - is a measure of the relative volume change of a fluid or solid as a response to a pressure (or mean stress) change. (D)
Flammability - ability of a chemical to burn or ignite, causing fire or combustion. (B)
Heat of Combustion - The amount of heat released per unit mass or unit volume of a substance when the substance is completely burned. (A)
Reactivity - the state or power of being reactive or the degree to which a thing is reactive (C)
Hope this helps!!
