Answer:
[OH⁻] = 0.0627M
pOH = 1.20
pH = 12.8
[H⁺] = 1.59x10⁻¹³M
Explanation:
To solve this question we must, as first, find the molarity of Al(OH)₃ in the solution -Molar mass Al(OH)₃: 78.00g/mol-:
0.300g * (1mol/ 78.00g) = 3.846x10⁻³ moles
In 184mL = 0.184L:
3.846x10⁻³ moles / 0.184L = 0.0209M Al(OH)₃. Three times this molarity = [OH⁻]:
[OH⁻] = 0.0209M * 3
<h3>[OH⁻] = 0.0627M</h3>
pOH = -log [OH⁻] =
<h3>pOH = 1.20</h3>
pH = 14 - pOH
<h3>pH = 12.8</h3>
And [H⁺] = 10^-pH
<h3>[H⁺] = 1.59x10⁻¹³M</h3>
<span>1. </span>To solve this we assume
that the gas is an ideal gas. Then, we can use the ideal gas equation which is
expressed as PV = nRT. At a constant temperature and number of moles of the gas
the product of PV is equal to some constant. At another set of condition of
temperature, the constant is still the same. Calculations are as follows:
P1V1 =P2V2
V2 = P1 x V1 / P2
V2 = 203 x 40.0 / 35.0
V2 =232 L
Answer:
The substance has a specific heat of 1.176 J/g°C
Explanation:
<u>Step 1: </u>Data given
Temperature change = 34 °C
Mass of the substance = 20 kg = 20000 grams
The substance gained 800 kJ of heat during this temperature change
<u>Step 2:</u> Calculate the specific heat
q = m*c*ΔT
⇒ with q = heat gained = 800 kJ = 800000 J
⇒ with m = the mass of the substance = 20 kg = 20000 grams
⇒ with c = the specific heat of the substance = TO BE DETERMINED
⇒ with ΔT = the change of temperature = T2 -T1 = 48° - 14 ° = 34°
c = q/(m*ΔT)
c = 800000 / (20000 * 34)
c = 1.176 J/g°C
The substance has a specific heat of 1.176 J/g°C
Answer:
D. -120.9 kJ
Explanation:
According to Hess's law ,the total enthalpy change for a reaction is the sum of all changes regardless of the stages or the steps of the reaction.
....(1)
(this reaction should be reversed in order to reach the required reaction )
On reversing the reaction the sign of get reversed.
(In this case change sign from '-' to'+'. Hence = + 65 kJ)
....(1)
......(2)
Adding equation (1) and (2)
(It is nearly equal to -120.9 kJ)