Answer:
744.9 mmHg ≅ 745 mmHg
Explanation:
The base to solve this, is the Ideal Gases Law. The mentioned formula is:
P . V = n . R . T
To compare two situations, we can propose:
For the first situation P₁ . V₁ = n₁. R . T₁
For the second situation P₂ . V₂ = n₂ . R . T₂
As the sample has the same moles and R is a constant value, we can avoid them so: (P₁ . V₁) / T₁ = (P₂ . V₂) / T₂
We need to make Tº unit conversion:
25ºC + 273 = 298K
We replace data → (370 mL . 1020 mmHg) / 298K = (P . 510 mL) / 300 K
(377400 mL.mmHg / 298K) . 300 K = P . 510 mL
379932.8 mL . mmHg = P . 510 mL
(379932.8 mL . mmHg) / 510 mL = P → 744.9 mmHg
To find the atomic mass of chlorine, the atomic mass of each isotope is multiplied by the relative abundance (the percent abundance in decimal form) and then the individual masses are added together. The atomic mass of chlorine is 35.45 amu.
Answer:
Explanation:
3. The number of electrons and neutrons in an atom are 13 and 14, respectively. Find out the mass number, atomic number, valency, and symbol of the element.
For a neutral atom. number of protons =number of electrons=13
so since atomic number is the number of protons =13
mass number = protons + neutons =14+13 = 27
atomic number 13 is Aluminum (AL-(see periodic table)
The electronic structure for 13 electrons is 1s2s2p63s23p1
so Al has 3 electrons which are VALIENT and can react and when it loses the 3 it will have CHARGE OF +3
Answer:
Na₂CO₃.2H₂O
Explanation:
For the hydrated compound, let us denote is by Na₂CO₃.xH₂O
The unknown is the value of x which is the amount of water of crystallisation.
Given values:
Starting mass of hydrate i.e Na₂CO₃.xH₂O = 4.31g
Mass after heating (Na₂CO₃) = 3.22g
Mass of the water of crystallisation = (4.31-3.22)g = 1.09g
To determine the integer x, we find the number of moles of the anhydrous Na₂CO₃ and that of the water of crystallisation:
Number of moles = 
Molar mass of Na₂CO₃ =[(23x2) + 12 + (16x3)] = 106gmol⁻¹
Molar mass of H₂O = [(1x2) + (16)] = 18gmol⁻¹
Number of moles of Na₂CO₃ = 
= 0.03mole
Number of moles of H₂O = 
= 0.06mole
From the obtained number of moles:
Na₂CO₃ H₂O
0.03 0.06
Simplest
Ratio 0.03/0.03 0.03/0.06
1 2
Therefore, x = 2
The question is incomplete, the complete question is;
In the 1800s, a popular belief known as vitalism stated that life processes could not be explained by the laws of physics and chemistry,and were instead dictated by an independent life force. Which discovery most likely caused scientists to revise this hypothesis regarding the origin of life on Earth?
a. that inorganic compounds existed within live organisms
b. that organic compounds could be synthesized in a laboratory
c. that RNA could serve as a template to synthesize DNA
d. that self-replicating molecules existed inside cells
Answer:
b. that organic compounds could be synthesized in a laboratory
Explanation:
Vitalism is the belief that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things"(wikipedia).
This theory held that the molecules involved in life processes could not be synthesized in the laboratory.
All these were upturned after Fredrich Whöler's synthesis of urea in 1828. He was able to show that molecules involved in life process can also be synthesized in the laboratory. This gave rise to modern synthetic organic chemistry.
