Aluminum is an element. Which best describes what makes up a sample of aluminum?
2 answers:
Answer: one kind of atom
Explanation:
Element is a pure substance which is composed of similar atoms.It can not be decomposed into simpler constituents using chemical reactions.Example: Aluminium
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water
Thus as aluminium is made up of one kind of atom , it is considered as an element.
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Answer:
0.44 moles
Explanation:
Given that :
A mixture of water and graphite is heated to 600 K in a 1 L container. When the system comes to equilibrium it contains 0.17 mol of H2, 0.17 mol of CO, 0.74 mol of H2O, and some graphite.
The equilibrium constant
The equilibrium constant
The equilibrium constant
Some O2 is added to the system and a spark is applied so that the H2 reacts completely with the O2.
The equation for the reaction is :
Total mole of water now = 0.74+0.17
Total mole of water now = 0.91 moles
Again:
0.03905(0.91 -x) = (0.17 +x)(x)
0.0355355 - 0.03905x = 0.17x + x²
0.0355355 +0.13095 x -x²
x² - 0.13095 x - 0.0355355 = 0
By using quadratic formula
x = 0.265 or x = -0.134
Going by the value with the positive integer; x = 0.265 moles
Total moles of CO in the flask when the system returns to equilibrium is :
= 0.17 + x
= 0.17 + 0.265
= 0.435 moles
=0.44 moles (to two significant figures)