The earth is a vast, complex system powered by two sources of energy: an internal source (the decay of radioactive elements in the geosphere, which generates geothermal heat) and an external source (the solar radiation received from the Sun); the vast majority of the energy in the earth system comes from the Sun.
Answer:
3.2 x 10²¹molecules
Explanation:
Given parameters:
Volume of nitrogen gas = 120cm³
Unknown:
Mass of nitrogen gas = ?
Number of molecules = ?
Solution:
To solve this problem, note that;
1 mole of gas occupies a volume of 22.4L at STP
Now;
convert 120cm³ to L ;
1000cm³ = 1L
120cm³ gives 0.12L
Since;
22.4L of gas has 1 mole at STP
0.12L of gas will have 
= 0.0054mole at STP
So;
Mass of N₂ = number of moles x molar mass
Molar mass of N₂ = 2(14) = 28g/mol
Mass of N₂ = 0.0054 x 28 = 0.15g
Now;
1 mole of a gas will have 6.02 x 10²³ molecules
0.0054 mole of N₂ will contain 0.0054 x 6.02 x 10²³ =
3.2 x 10²¹molecules
Answer:
a) the reverse reaction is favoured
b) the forward reaction is favoured
c) the forward reaction is favoured
Explanation:
The equation ought to have been correctly written as;
3A + 2B --------> C + 2D. ∆H =20 kJ
Actually, we can see that the reaction is endothermic since ∆H= positive.
We know that when pressure is decreased, the reaction tends towards the side with higher total volumes. There are five volumes(moles) of reactants and three volumes(moles) of products. A decrease in pressure will favour the reverse reaction.
Being an endothermic reaction, increase in temperature is known to favour the forward reaction. Similarly, removing D will drive the equilibrium forward thereby favouring the forward reaction.
D. A broken piece of quartzite will break through, not around, quartz sand grains.
Quartzite and quartz sandstone have the <em>same chemical formula</em> (SiO_2)
Quartzite is a <em>metamorphic rock</em>. Heat and pressure have compressed the sand into a strong network of interlocking quartz grains.
Quartzite is so tough that it breaks through the sand grains rather than around them as in sandstone.
