There are several differences between<span> a </span>physical and chemical change<span> in matter or substances. A </span>physical change<span> in a substance doesn't </span>change<span> what the substance is. In a </span>chemical change<span> where there is a </span>chemical<span> reaction, a new substance is formed and energy is either given off or absorbed.</span>
Answer:
The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol
Explanation:
The ∆H (heat of reaction) of the combustion reaction is the heat that accompanies the entire reaction. For its calculation you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient (number of molecules of each compound that participates in the reaction) and finally subtract them:
Enthalpy of the reaction= ΔH = ∑Hproducts - ∑Hreactants
In this case, you have: 2 NOCl(g) → 2 NO(g) + Cl₂(g)
So, ΔH=
Knowing:
- ΔH= 75.5 kJ/mol
= 90.25 kJ/mol
= 0 (For the formation of one mole of a pure element the heat of formation is 0, in this caseyou have as a pure compound the chlorine Cl₂)
=?
Replacing:
75.5 kJ/mol=2* 90.25 kJ/mol + 0 - 
Solving
-
=75.5 kJ/mol - 2*90.25 kJ/mol
-
=-105 kJ/mol
=105 kJ/mol
<u><em>The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol</em></u>
Answer:
The Flow rate = 0.0208 mL/min
Explanation:
Data provided:
Rate of dose = 39 mg every 30 min = (39/30) mg/min = 1.3 mg/min
also,
125mg of methylprednisolone is present in every 2 mL
thus,
concentration = (125/2) mg/mL = 62.5 mg/mL
Now,
The flow rate is given as:
Flow rate = Rate / Concentration
on substituting the respective values, we get
Flow rate = (1.3 mg/min) / (62.5mg/mL)
or
The Flow rate = 0.0208 mL/min
Answer:
You can see that the line is going up and is curved in a positive direction.
Explanation:
When an object is speeding up, the acceleration is in the same direction as the velocity. Thus, this object has a positive acceleration.