Molar mass of FE2O3=2(55.85)+3(16)=159.7
2.56g*1mol/159.7*2mol/1mol*55.85g/1mol=1.79g
The balanced equation for the reaction is as follows;
Ca(OH)₂ + 2HBr --> CaBr₂ + 2H₂O
stoichiometry of Ca(OH)₂ to HBr is 1:2
number of Ca(OH)₂ moles reacted - 0.10 mol/L x 0.1000 L = 0.010 mol
Number of HBr moles added - 0.10 mol/L x 0.4000 = 0.040 mol
1 mol of Ca(OH)₂ needs 2 mol of HBr for neutralisation
therefore 0.010 mol of Ca(OH)₂ needs - 0.010 x 2 = 0.020 mol of HBr to be neutralised
but 0.040 mol of HBr has been added therefore number of moles of HBr in excess - 0.040 - 0.020 = 0.020 mol
then pH of the medium can be calculated using the excess H⁺ ions
HBr is a strong acid therefore complete ionization
[HBr] = [H⁺]
[H⁺] = 0.020 mol / (100.0 + 400.0 mL)
= 0.020 mol / 0.5 L
= 0.040 mol/L
pH = -log[H⁺]
pH = - log [0.040 M]
pH = 1.40
pH of the medium is 1.40
It has 7.22 moles.... mole =mass/molar mass
molar mass of H2O=18
130/18=mole
The answer is 4 (four).
Hope this helps!!! :)
Answer:
420 miles
Explanation:
From the question given above, the following data were obtained:
Time = 3.5 hours
Speed = 120 mi/h
Distance =?
Speed is defined as the distance travelled per unit time. Mathematically, it is expressed as:
Speed = distance / time
With the above formula, we can obtain the distance travelled by the plane as follow:
Time = 3.5 hours
Speed = 120 mi/h
Distance =?
Speed = distance / time
120 = distance / 3.5
Cross multiply
Distance = 120 × 3.5
Distance = 420 miles
Thus, the distance travelled by the plane is 420 miles
