Answer:
86.2 g/mol
Explanation:
Before you can find the molar mass, you first need to calculate the number of moles of the gas. To find this value, you need to use the Ideal Gas Law:
PV = nRT
In this equation,
-----> P = pressure (mmHg)
-----> V = volume (L)
-----> n = moles
-----> R = Ideal Gas constant (62.36 L*mmHg/mol*K)
-----> T = temperature (K)
After you convert the volume from mL to L and the temperature from Celsius to Kelvin, you can use the equation to find the moles.
P = 760 mmHg                                      R = 62.36 L*mmHg/mol*K
V = 250 mL / 1,000 = 0.250 L              T = 20 °C + 273.15 = 293.15 K
n = ? moles 
PV = nRT
(760 mmHg)(0.250 L) = n(62.36 L*mmHg/mol*K)(293.15 K)
190 = n(18280.834)
0.0104 = n
The molar mass represents the mass (g) of the gas per every 1 mole. Since you have been given a mass and mole value, you can set up a proportion to determine the molar mass.
                                      <----- Proportion
                       <----- Cross-multiply
                                               <----- Divide both sides by 0.0104
 
        
             
        
        
        
Answer:
The metal element → Magnesium (Mg)
 
        
                    
             
        
        
        
Answer:
Explanation:
100 miles * [ 5280 feet / 1 mile] * 12 inches / 1 foot]
100 * 5280 * 12 inches
6336000 inches in 100 miles
 
        
             
        
        
        
a. W = 0 J
b. W = - 308.028 J
<h3>Further explanation</h3>
Given
Nitrogen gas expands in volume from 1.6 L to 5.4 L
Required
The work done
Solution
Isothermal :
W = -P . ΔV
Input the value :
a. At a vacuum, P = 0
So W = 0
b. At pressure = 0.8 atm
W = - 0.8 x ( 5.4 - 1.6)
W = -3.04 L.atm ( 1 L.atm = 101.325 J)
W = - 3.04 x 101.325 
W = - 308.028 J
 
        
             
        
        
        
Answer:
Antoine Lavoisier and Johann Wolfang Döbereiner organized the elements based on properties such as how the elements reacts or whether they are solid or liquid.
Explanation:
The periodic table of the elements as we have it today was developed as a result of the work of several notable centuries who lived centuries apart, all of who made notable contributions to development of the modern periodic table in use today.
In 1789, Antoine Lavoisier, a French Chemist provided a definition of elemets which he defined as a substance whose smallest units cannot be broken down into a simpler substance. He further grouped the elements into two as metals and nonmetals. 
In 1829, German physicist Johann Wolfang Döbereiner arranged elements in groups of three in increasing order of atomic weight and called them triads. His arrangement owasf elements into triads was based on his observation of similarities in physical and chemical properties of certain elements.
John Newlands, a British Chemist was the first to arrange the elements into a periodic table with increasing order of atomic masses.
In 1869, Russian chemist Dmitri Mendeleev developed a periodic table which provided a framework the modern periodic table. He arranged the elements according to their atomic weight, leaving gaps for elements that were yet to be discovered.
The modern periodic table arranges elements based on increasing atomic number.