Answer:
The correct answer is option B.
Explanation:
Significant figures :These are figures in a number which expresses the value of the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Significant digits in the volume measurement 0.010 mL are:
= 2 significant figures
The volume measurement "0.010 mL" contains two significant digits. Significant digits are nonzero digits and trailing zeros in decimal numbers that contribute to the precision of the measurement.
In the volume measurement "0.010 mL," there are two significant digits. Significant digits are the digits in a measured quantity that contribute to its precision or accuracy. To identify significant digits, consider the following rules:
1. All nonzero digits are significant. In this case, "0" is considered a nonzero digit because it appears between two nonzero digits.
2. Leading zeros (zeros to the left of the first nonzero digit) are not significant. In "0.010 mL," the leading zero is not considered a significant digit.
3. Trailing zeros (zeros to the right of the last nonzero digit) in a decimal number are significant. So, the two trailing zeros in "0.010 mL" are significant.
Therefore, the measurement "0.010 mL" has two significant digits (the "1" and the "0"), and the correct answer is B) 2. These two significant digits represent the precision of the volume measurement.
Learn more about significant digits here:
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The rule used for the determination of the protons, electrons, and neutrons has been the equal number of protons and electrons, while the number of the neutrons has been the difference in the atomic mass and the protons.
The atom has been the smallest particle that has comprised of electrons, protons, and neutrons as the subatomic particle. The neutrons and protons in the atoms have consisted within the nucleus. The electrons in the atom are revolving around the nucleus.
The atoms have been consisted of an equal number of protons and electrons, while the number of neutrons has been the difference in the atomic mass and the protons.
The ions have been formed with the loss or gain of the electrons by the atom in the terms of valence electrons to complete its octet.
For more information about the electrons and protons, refer to the link:
Answer:
Explanation:
This question appears incomplete, however
The number of protons of an element/atom (atomic number) can be determined by checking for the position of the element on the periodic table. This is because elements are arranged according to there atomic number on the periodic table.
The number of electrons of any element (of a neutral atom) is equal to the number of protons of the same element.
The number of neutrons of an element/atom is determined by subtracting the atomic number of the element from it's mass number. Hence, mass number is the addition of the atomic number and the number of neutrons.
Ions are charged particles that have the same number of protons and neutrons as there parent atoms. Hence, they have different number of electrons when compared to there specific parent/neutral atom.
A negatively charged atom has more electrons than it's original atom. For example, fluoride ion (F⁻) has 10 electrons while fluorine atom has 9 electrons (meaning fluoride ion has one more electron than it's parent fluorine). The increase is dependent on the number "attached" to the charge. A positively charged atom has less electrons than it's original atom. For example, calcium ion (Ca²⁺) has 18 electrons while calcium atom has 20 electrons (meaning the calcium ion has 2 electrons less than it's parent calcium atom). As said earlier, the decrease here is also dependent on the number "attached" to the charge.
(ii) 2-bromo-2-methylpentane.
Answer:
The mechanisms for the elimination reactions between NaOH in ethanol and the halogenoalkanes are demonstrated in the figure attached.
Explanation:
(i) 1-bromobutane will suffer elimination to for an alkene. The mechanism will be E2, which means that the attack and the elimination will occur simultaneously. This is the preferred mechanism because the bromine is in a primary carbon.
(ii) 2-bromo-2-methylpentane will suffer elimination to for an alkene. The mechanism will be E1, which means that the attack and the elimination will occur in two different steps. The bromine will be eliminated in the first step with the formation of a carbocation and in a second step the double bond will be formed after the anionic attack. This is the preferred mechanism because the bromine is in a terciary carbon which is able to stabilize the carbocation formed.
Answer:
400 Joules
Explanation:
From the question,
The total kinetic energy of the water balling when hits the ground is given as
K.E = 1/2mv².................. Equation 1
Where K.E = Kinetic Energy of water ballon, m = mass of water balloon, v = velocity of water ballon
Given: m = 2 kilograms, v = 20 meters/second.
Substitute these values into equation 1
K.E = (2×20²)/2
K.E = 2×400/2
K.E = 400 Joules
Answer:
the answer 37
Explanation:
Answer:
49.4 mol Oxygen
Explanation:
Mg(NO3)2 ----- 6 O
1 mol 6 mol
8.24 mol x mol
x = 8.24*6/1 = 49.44 mol ≈ 49.4 mol Oxygen
The value of the van't Hoff factor for the given solute is 2.7
Option (A) 2.7 is correct.
The Van't Hoff factor is a measure of a solute's effect on colligative qualities such boiling point elevation, osmotic pressure, and relative vapor pressure reduction.
Given,
Molar mass is 132.15 g/mol
Boiling point elevation is 102.5 °C
kb for water is 0.512°c/m
Molarity of solution is 1.83 m
The value of van't Hoff factor is: 2.66 or 2.7 (approx)
Now, from the solution of colligative properties to calculate elevation in boiling point.
where Δ = elevation of boiling point (102.5)
Thus, The value is 2.7 option (A) is correct.
Learn more about van't Hoff factor, here:
We need to know the value of van't hoff factor.
The van't hoff factor is: 2.66 or 2.7 (approximately)
(NH₄)₂SO₄ is an ionic compound, so it dissociates in solution and produces 3 ionic species. Therefore van't hoff factor is more than one.
From the equation: Δ=i .m, where Δ= elevation of boiling point=102.5 - 100=2.5°C.
m=molality of solute=1.83 m (Given)
= Ebullioscopic constant or Boiling point elevation constant= 0.512°C/m (Given)
i= Van't Hoff factor
So, 2.5= i X 0.512 X 1.83
i=
i=2.66= 2.7 (approx.)