he showed that oxygen is required to burn.
Answer:
94.2 g/mol
Explanation:
Ideal Gases Law can useful to solve this
P . V = n . R . T
We need to make some conversions
740 Torr . 1 atm/ 760 Torr = 0.974 atm
100°C + 273 = 373K
Let's replace the values
0.974 atm . 1 L = n . 0.082 L.atm/ mol.K . 373K
n will determine the number of moles
(0.974 atm . 1 L) / (0.082 L.atm/ mol.K . 373K)
n = 0.032 moles
This amount is the weigh for 3 g of gas. How many grams does 1 mol weighs?
Molecular weight → g/mol → 3 g/0.032 moles = 94.2 g/mol
Answer:
Explanation:
Molar mass of Argon
= 35.96755 x .00337 + 37.96272 x .00063 + 39.96240 x .99600
= .12121 + .0239165 + 39.80255
= 39.95
Molar mass of silicon
27.97693 x .9223 + 28.97649 x .0467 + 29.97376 x .0310
= 25.803 + 1.35320 + .929
= 28.08
b )
No of atoms of Si in 78.2 g = 78.2 x 6.02 x 10²³ / 28.08
= 16.76 x 10²³ .
c )
42 Ar / 40 Ar = 1.05006
42 Ar / 39.95 = 1.05006
42Ar = 41.95
2 )
C₁₆H₁₅F₂N₃O₄S
Mol weight = 16 x 12 + 1 x 15 + 2 x 19 + 3 x 14 + 4 x 16 + 32
= 192 + 15 + 38 + 42 + 64+ 32
= 383
No of molecules = .078 x 6.02 x 10²³ / 383
= 1.226 x 10²⁰ molecules .
Döbereiner grouped the known elements into <em>triads</em> (sets of three) so that
• The <em>atomic mass of the middle element</em> was approximately the average of the other two
• The <em>chemical properties of the middle element</em> were between those of the other two
• The <em>physical properties of the middle element</em> were between those of the other two
One example of a triad is Li – Na – K.
(a) Atomic mass of Na = 23.0 u
Average atomic mass of Li and K = (6.9 u + 39.1 u)/2 = 46.0 u/2 = 23.0 u
(b) Li reacts slowly with water. Na reacts rapidly. Potassium reacts violently.
(c) Melting point of Na = 371 °C.
Average melting point of Li and K = (454 °C + 330 °C)/2 = 784 °C/2
= 392 °C
<u>Answer:</u>
<u>Plasmas of great interest to scientists or manufacturers as</u>
- Plasma is electrically charged gases that contain considerable charged particles that can change the behavior of the substance.
<u>Current uses of plasmas:</u>
- First, it is used to make semiconductors for different types of electronic equipment
- Secondly, they're used in making transmitters for high-temperature films.
<u>Way scientists and engineers hope to use plasmas in the future:</u>
- The scientists are hoping to use plasma in the future to get rid of all hazardous wastes through a process called plasma gasification.
