One atom of carbon weighs exactly 12/6.022x10^23 = 1.9927x10^-23 grams<span>.</span>
Answer:
Mass = 8 g
Explanation:
Given data:
Mass of MgO formed = 20 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of MgO:
Number of moles = mass/molar mass
Number of moles = 20 g/ 40 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of MgO and O₂ from balance chemical equation:
MgO : O₂
2 : 1
0.5 : 1/2×0.5 = 0.25 mol
Mass of oxygen required:
Mass = number of moles × molar mass
Molar mass of O₂ is 32 g/mol
Mass = 0.25 mol × 32 g/mol
Mass = 8 g
<h3>
Answer:</h3>
The root mean square speeds of O₂ and UF₆ is 513m/s and 155 m/s respectively.
<h3>
Solution and Explanation:</h3>
- To find how fast molecules or particles of gases move at a particular temperature, the root mean square speed is calculated.
- Root mean square speed of a gas is calculated by using the formula;
Where R is the molar gas constant, T is the temperature and M is the molar mass of gas in Kg.
<h3>Step 1: Root mean square speed from O₂</h3>
Molar mass of Oxygen is 32.0 g/mol or 0.032 kg/mol
Temperature = 65 degrees Celsius or 338 K
Molar gas constant = 8.3145 J/k.mol
<h3>
Step 2: Root mean square speed of UF₆ </h3>
The molar mass of UF₆ is 352 g/mol or 0.352 kg/mol
Therefore; the root mean square speeds of O₂ and UF₆ is 513m/s and 155 m/s respectively.
TRUE. (Lorenzo Romano Amadeo Carlo Avogadro) Ideal Gas Law that defined as one in which all collisions between atoms or molecules are perfectly elastic in which there are no intermolecular attractive forces. In such a gas, all the internal energy is the form of kinetic energy and any change in internal energy is accompanied by a change in temperature. That characterized by three state variables: absolute pressure (P) = 1 atm, volume (V) = 22.4 L and absolute temperature (T) = 273 K.
<span>Pre-1982 definition of STP: 37 g/mol
Post-1982 definition of STP: 38 g/mol
This problem is somewhat ambiguous because the definition of STP changed in 1982. Prior to 1982, the definition was 273.15 K at a pressure of 1 atmosphere (101325 Pascals). Since 1982, the definition is 273.15 K at a pressure of exactly 100000 Pascals). Because of those 2 different definitions, the volume of 1 mole of gas is either 22.414 Liters (pre 1982 definition), or 22.71098 liters (post 1982 definition). And finally, there's entirely too many text books out there that still use the 35 year obsolete definition. So let's solve this problem using both definitions and you need to pick the correct answer for the text book you're using.
First, determine how many moles of gas you have. Just simply divide the volume you have by the molar volume.
Pre-1982: 2.1 / 22.414 = 0.093691443 moles
Post-1982: 2.1 / 22.71098 = 0.092466287 moles
Now determine the molar mass. Simply divide the mass by the moles. So
Pre-1982: 3.5 g / 0.093691443 moles = 37.35666667 g/mol
Post-1982: 3.5 g / 0.092466287 moles = 37.85163333 g/mol
Finally, round to 2 significant figures. So
Pre-1982: 37 g/mol
Post-1982: 38 g/mol</span>
