Answer:
true. m (↑) ⇒ n (↑)
Explanation:
- mass (m) ≡ moles ( n) × moleculas weight ( Mw )
In the previous expression, we appreciate that the mass is directly proportional to the moles; therefore, if the mass of the sample increases, its number of moles will also increase, since the molecular weight is always constant.
∴ m (↑) ⇒ n (↑)
Answer:
(A) 28
Explanation:
To solve this problem we use the <em>PV=nRT equation</em>, where:
- P = 800 mmHg ⇒ 800/760 = 1.05 atm
- R = 0.082 atm·L·mol⁻¹·K⁻¹
- T = 25.0 °C ⇒ 25.0 + 273.16 = 298.16 K
We<u> input the data</u>:
- 1.05 atm * 2.00 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K
And <u>solve for n</u>:
Now we calculate the gas' mass:
- Gas Mass = (Mass of Container w/ Gas) - (Mass of Empty Container)
- Gas Mass = 1052.4 g - 1050.0 g = 2.4 g
Finally we <u>calculate the unknown gas' molar mas</u>s, using<em> its mass and its number of moles</em>:
- Molar Mass = mass / moles
- Molar Mass = 2.4 g / 0.086 mol = 27.9 g/mol
So the answer is option (A).
Answer:
17.76g
Explanation:
We need to write a balanced chemical equation for the reaction:
2Al(OH)3 + 3Ca(NO3)2 ——> 3Ca(OH)2 + 2Al(NO3)3
In the reaction above, it can be seen that 2 moles of aluminum hydroxide yielded 3 moles of calcium hydroxide. This is the theoretical viewpoint.
Now we need to know what actually happened. We need to calculate the actual number of moles of aluminum hydroxide reacted l. We can get this by dividing the mass by the molar mass.
The molar mass of aluminum hydroxide is 27+ 3( 16+1)
= 27 + 51 = 78g/mol
The number of moles is thus: 12.55/78 = 0.16 moles
Now if 2 moles of aluminum hydroxide gave 3 moles of calcium hydroxide, 0.16moles will give : (0.16*3)/2 = 0.24moles
Now we can calculate the mass of calcium hydroxide formed. The mass of calcium hydroxide formed is the number of moles multiplied by the molar mass.
The molar mass of calcium hydroxide is; 40 + 2(17) = 74g/mol
The mass is thus =74 * 0.24 = 17.76g
The bonds of a glucose molecule store chemical energy
An enema administration is a technique used to stimulate stool evacuation The process helps push waste out of the rectum when you cannot do so on your own
