Answer:
8.8g of Al are necessaries
Explanation:
Based on the reaction, 2 moles of Al are required to produce 3 moles of hydrogen gas.
To solve this question we must find the moles of H2 in 11L at STP using PV = nRT. With these moles we can find the moles of Al required and its mass as follows:
<em>Moles H2:</em>
PV = nRT; PV/RT = n
<em>Where P is pressure = 1atm at STP; V is volume = 11L; R is gas constant = 0.082atmL/molK and T is absolute temperature = 273.15K at STP</em>
Replacing:
1atm*11L/0.082atmL/molK*273.15K = n
n = 0.491 moles of H2 must be produced
<em />
<em>Moles Al:</em>
0.491 moles of H2 * (2mol Al / 3mol H2) = 0.327moles of Al are required
<em />
<em>Mass Al -Molar mass: 26.98g/mol-:</em>
0.327moles of Al * (26.98g / mol) = 8.8g of Al are necessaries
What are the phrases to choose from?
Answer:
The change in internal energy of the heater is 0 kJ
Explanation:
∆U = Q - W
Q is quantity of heat transferred = 1 kJ
W is work done on the heater = 1 kJ
Change in internal energy (∆U) = 1 - 1 = 0 kJ
The two properties which are used to define matter are that it has mass
and it takes up space. The other properties do not necessarily apply to
each matter. Such some matter can be a conductor of heat (such as metal)
and some not (such as non metals). Likewise, some matter can be buoyant
and float on liquid of density more than it but others would not on the
liquids of density less than it. In-fact not all the matters are
conductors of energy (such as heat, sound, electricity) or at-least a
very poor conductor of energy and tend to find application as
insulating agents (non conductors). So the only thing which is
necessarily true is that the matter would definitely have mass in even
their minutest form as atom and would take up some space.
