Answer:
93.17 g
Explanation:
Recall that: mol = mass/molar mass
Also; mol = molarity x volume
mole of (NH4)2SO4 to be prepared = 282/1000 (dm3) x 2.50 (mol/dm3)
= 0.705 mol
This can be used to determine the mass of (NH4)2SO4 that will be required.
mass = mole x molar mass
Hence, mass of (NH4)2SO4 required = 0.705 x 132.15
= 93.17 g
Hence, the mass of ammonium sulfate that will be required to prepare 282 mL of a 2.50M solution is 93.17 g
The cation is smaller.
Electronic configuration of Lithium atom is as follow,
Li = 1s², 2s¹
while, Electronic configuration of Lithium cation is as follow,
Li⁺ = 1s²
The Lithium Cation is smaller because,
i) Less Energy Levels:
As depicted in electronic configurations, the valence shell of Li atom is 2 while, that of Li cation is 1 as a result the distance of valence electrons and nucleus has decreased resulting in small size.
ii) Less Shielding Effect:
The effect in which the core electrons shield the valence electron from nucleus pull is known as shielding effect. In Li cation there are no core electrons hence, the electrons are more attracted towards proton resulting in small size.
iii) More Nuclear Charge:
In Li atom there are three protons and three electrons so, three protons attract three electrons and the game run some what balance. But, as tone electron is lost in Li Cation, the proton side gets stronger and apply more pull on electrons and made them more closer to the nucleus resulting in size decrease.
The correct statement is: The cation is smaller.
In a neutral lithium atom, there are three electrons surrounding the nucleus, distributed in different energy levels or electron shells. These electrons repel each other due to their negative charges, creating an electron-electron repulsion that tends to spread them out and increase the size of the atom.
When a lithium atom loses one electron to form a cation, it becomes positively charged. This loss of an electron reduces the electron-electron repulsion within the atom. With fewer electrons, the remaining electrons experience a stronger attraction towards the nucleus, since the positive charge of the nucleus is no longer balanced by the negative charge of the lost electron.
As a result, the remaining electrons are drawn closer to the nucleus in the lithium cation. The reduction in electron-electron repulsion and the increased attraction between the electrons and the nucleus cause the cation to have a smaller size compared to the neutral atom.
Hence, the lithium cation (Li⁺) is smaller than the lithium atom (Li)
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Carbon-12 Atom is correct :)
Answer : The percent by mass of oxygen in propanal is, 27.58 %
Solution : Given,
Molar mass of carbon = 12 g/mole
Molar mass of hydrogen = 1 g/mole
Molar mass of oxygen = 16 g/mole
First we have to calculate the molar mass of propanal,
Molar mass of propanal, =
Now we have to calculate the percent by mass of oxygen in propanal.
Therefore, the percent by mass of oxygen in propanal is, 27.58 %
B They both dissociate completely, with little or no reverse reactions.
C They both remain intact when placed in water, with no dissociation taking place.
D They both dissociate completely, with reverse reactions constantly taking place.
2 What happens when the kinetic energy of molecules increases so much that electrons are released by the atoms, creating a swirling gas of positive ions and negative electrons?
A Matter changes to a solid state.
B Matter changes to a liquid state.
C Matter changes to a plasma state.
D Matter changes to a gaseous state.
3 Consider a balloon that has a volume V. It contains n moles of gas, it has an internal pressure of P, and its temperature is T. If the balloon is heated to a temperature of 15.5T while it is placed under a high pressure of 15.5P, how does the volume of the balloon change?
A It doubles.
B It stays the same.
C It increases greatly.
D It decreases slightly.
1) Answer is: B They both dissociate completely, with little or no reverse reactions.
Some of strong acids: HNO₃(nitric acid), HCl(hydrochloric acid), H₂SO₄(sulfuric acid), HI(hydroiodic acid). Strong bases are: sodium hydroxide (NaOH), barium hydroxide (Ba(OH)₂).
For example, hydrochloric acid, completely dissociate in water and give large amount of hydrogen ions (H⁺): HCl(aq) → H⁺(aq) + Cl⁻(aq).
Sodium hydroxide completely dissociate in water:
NaOH(aq) → Na⁺(aq) + OH⁻(aq).
2) Answer is: C Matter changes to a plasma state.
Plasma is a an ionised gas with highly electrical conductivity.
In solid, molecules are closely packed, stiff and do not changes of shape or volume. Solid object (for example iron) does not take on the shape of its container.
Liquids have definite volume, but no fixed shape.
Gases (for example nitrogen and neon) not have definite volume and fixed shape, it depends on its container.
3) Answer is: B It stays the same.
p₁ = P; initial pressure.
p₂ = 15.5 P; final pressure.
V₁ = V: initial volume.
V₂ = ?: final volume.
T₁ = T; initial temperature.
T₂ = 15.5T; final temperature.
The combinated gas law: The volume of a given amount of gas is proportional to the ratio of its Kelvin temperature and its pressure: p₁·V₁/T₁ = p₂·V₂/T₂.
P·V/T = (15.5P · V₂) / 15.5 T.
V₂ = V₁ = V.
Answer:
1). B
2). C
3). B
Explanation:
B
C
The wave with the longest wavelength is (A,B,C). The wave with the smallest amplitude is (A,B,C). The wave with the most energy is (A,B,C).
A is the wave with the longest wavelength. The graph clearly shows this since wave A has a larger wavelength than waves B and C. Wave A has the longest wavelength when compared to the other two waves.
C is the wave with the least amplitude. The graph shows this since wave C has a significantly lesser amplitude than waves A and B. Wave C has the least amplitude when compared to the other two waves. B is the most energetic wave.
The graph shows this because wave B has a larger amplitude than waves A and C. Wave B has the greatest amplitude when compared to the other two has the more energy in comparison to the two.
The longest wavelength wave has the lowest frequency and the lowest energy. A wave's wavelength is inversely related to its frequency, which implies that as the wavelength grows, so does the frequency. Because energy is proportional to frequency, the wave with the longest wavelength has the least energy.
The wave with the smallest amplitude has the least amount of energy. The largest displacement of a wave from its equilibrium position is referred to as its amplitude. The energy of a wave is exactly proportional to its amplitude, therefore as the amplitude falls, so does the energy.
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b. polyatomic ion
c. multivalent ion
d. electron ion
Answer:
The correct answer is option b, that is, polyatomic ion.
Explanation:
A molecular ion also called polyatomic ion refers to a charged chemical species comprising two or more atoms bonded covalently with each other. The polyatomic ions comprise two or more non-metallic atoms. An example of a polyatomic ion is an ion of nitrate that comprises one atom of nitrogen and three atoms of oxygen. As the atoms in a polyatomic ion are bonded covalently, they are considered to possess a single charged unit.