Answer:
84.24 g
Explanation:
Given data:
Mass of oxygen = 75 g
Mass of Al required to react = ?
Solution:
Chemical equation:
4Al + 3O₂ → 2Al₂O₃
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 75 g/ 32 g/mol
Number of moles = 2.34 mol
Now we will compare the moles of oxygen with Al.
O₂ : Al
3 : 4
2.34 : 4/3×2.34 = 3.12 mol
Mass of Al required:
Mass = number of moles × molar mass
Mass = 3.12 mol × 27 g/mol
Mass = 84.24 g
11. I would say physical because the color of the item is changed and the texture and density is changed aswell.
Answer: A balloon is charged by a process of frictional charging and the object is getting charged by the process of induction.
Explanation:
When two bodies are rubbed against each other, charging by friction or rubbing occurs. The electropositive object loses electrons to electronegative object. Thus, when balloon is rubbed on a wall, it becomes charged.
The charged balloon is able to attract an uncharged object by inducing charge on it without the two objects touching each other. Electrostatic force acts between two charged objects. Charged balloon causes electrons to move at one end thereby inducing opposite charge in the object and thus, charged balloon is able to attract uncharged object.
Answer:
See solution.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to set up the formula for the calculation of the by-mass percentage of the metal:
Thus, we solve for the molar mass of the metal to obtain:
For the subsequent problems, we proceed as follows:
a.
b.
c.
Regards!
Answer:
the molarity is 3.68 moles/L
Explanation:
the molality of the solution of sucrose is
m= moles of glucose / Kg of solvent (water)= 6.81 ,
since the molecular weight of glucose is 180.156 gr/mole , then per each kilogram of solvent there is
6.81 moles*180.156 gr/mole + 1000 gr of water = 2226.86 gr of solution
from the density
volume of solution = mass of solution/density = 2286.86 gr / 1.2 gr/ml = 1855.71 ml
therefore there is 1000 gr of water in 1855.71 ml
then the molarity M is
M= moles of glucose / L of solution = (moles of glucose / Kg of solvent) * (Kg of solvent/L of solution) = 6.81 moles/Kg * 1Kg/1.85 L = 3.68 moles/L
M= 3.68 moles/L
Note:
- Would be wrong in this case to assume density of water = 1 Kg/L since the solution is heavily concentrated in glucose and therefore the density of water deviates from its pure value.
