His work foreshadowed the periodic table. He tried organizing elements into triads, a set of 3 elements with similar properties. In each triad the mean of the lightest and heaviest atomic weight equaled to approximately the atomic weight of the middle element.
Answer: (1). There are 0.0165 moles of gaseous arsine (AsH3) occupy 0.372 L at STP.
(2). The density of gaseous arsine is 3.45 g/L.
Explanation:
1). At STP the pressure is 1 atm and temperature is 273.15 K. So, using the ideal gas equation number of moles are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
2). As number of moles are also equal to mass of a substance divided by its molar mass.
So, number of moles of Arsine (molar mass = 77.95 g/mol) is as follows.
Density is the mass of substance divided by its volume. Hence, density of arsine is calculated as follows.
Thus, we can conclude that 0.0165 moles of gaseous arsine (AsH3) occupy 0.372 L at STP and the density of gaseous arsine is 3.45 g/L.
Answer:
first first row: element
second first row :compound
The white phosphorus, is very reactive with the atmosphere enters the point of ignition ,causing <span>explosion.
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The answer is:
C. Fluorine is more reactive than nitrogen because fluorine needs only one electron to fill its outermost shell.