Answer:
Mass = 18.9 g
Explanation:
Given data:
Mass of Al₂O₃ formed = ?
Mass of Al = 10.0 g
Solution:
Chemical equation:
4Al + 3O₂ → 2Al₂O₃
Number of moles of Al:
Number of moles = mass/molar mass
Number of moles = 10.0 g/ 27 g/mol
Number of moles = 0.37 mol
Now we will compare the moles of Al and Al₂O₃.
Al : Al₂O₃
4 : 2
0.37 : 2/4×0.37 = 0.185 mol
Mass of Al₂O₃:
Mass = number of moles × molar mass
Mass = 0.185 mol × 101.9 g/mol
Mass = 18.9 g
Answer:
∆H > 0
∆Srxn <0
∆G >0
∆Suniverse <0
Explanation:
We are informed that the reaction is endothermic. An endothermic reaction is one in which energy is absorbed hence ∆H is positive at all temperatures.
Similarly, absorption of energy leads to a decrease in entropy of the reaction system. Hence the change in entropy of the reaction ∆Sreaction is negative at all temperatures.
The change in free energy for the reaction is positive at all temperatures since ∆S reaction is negative then from ∆G= ∆H - T∆S, we see that given the positive value of ∆H, ∆G must always return a positive value at all temperatures.
Since entropy of the surrounding= - ∆H/T, given that ∆H is positive, ∆S surrounding will be negative at all temperatures. This is so because an endothermic reaction causes the surrounding to cool down.
Answer:
d. compound
Explanation:
<u>Mixture </u>: It is defined as the substance that is made by the combination of two or more different components which are physically combined.
<u>Homogeneous mixture</u> are the mixtures in which the composition of the substances in it are uniformly mixed. <u>Heterogeneous mixture</u> are the mixtures in which the composition of the substances in it are not uniformly mixed.
<u>
Compound :</u> It is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass and are chemically bonded.
<u>
Element :</u> It is a pure substance which is composed of atoms of similar elements.
<u>As discussed above, The different elements in the compounds are chemically bonded and hence, it is the substance which can be broken down into the simpler units when it subtend only by the chemical change.</u>
