The ML of 0.85 m NaOH required to titrate 25 ml of 0.72m hbr to the equivalence point is calculated as follows
calculate the moles of HBr used
moles = molarity x volume
25 x0.072/1000= 0.0018 moles
write the equation for reaction
NaOH + HBr = NaBr + H2O
from reacting equation the mole ratio between NaOH to HBr is 1:1 therefore the moles of NaOH = 0.0018 moles
volume = moles/molarity
0.0018/0.085 = 0.021 L in Ml = 0.021 x1000=21.18 Ml ofNaOH
45 molecules of chlorine gas (Cl₂) are needed to react with 30 atoms of aluminum (Al)
The balanced equation for the reaction is given below:
2Al + 3Cl₂ —> 2AlCl₃
From the balanced equation above,
2 atoms of Al required 3 molecules of Cl₂.
With the above information, we can determine the number of molecules of Cl₂ needed to react with 30 atoms of Al. This can be obtained as follow:
From the balanced equation above,
2 atoms of Al required 3 molecules of Cl₂.
Therefore,
30 atoms of Al will require = 
= 45 molecules of Cl₂.
Thus, 45 molecules of chlorine gas (Cl₂) are needed to react with 30 atoms of aluminum (Al)
Learn more: brainly.com/question/24918379
Answer:
This question is incomplete
Explanation:
There are two major forms of energy; these are potential and kinetic energy. Kinetic energy is the energy present in moving options. Examples include mechanical and electrical energy.
The formula for kinetic energy is 1/2mv² where "m" is mass and "v" is velocity.
While potential energy is the energy present in stationary objects that can be put to use in future. Example includes a ball in its resting state. The formula for potential energy is "mgh" where "m" is mass, "g" is acceleration due to gravity and "h" is height
Considering the law of conservation of energy which states that energy can neither be created nor destroyed but can be transformed from one form to another. Looking at the example provided earlier for potential energy, a ball in its resting position (having a potential energy) when kicked will have a kinetic energy (which can be calculated with the formula provided earlier), hence
Total energy = potential energy (P.E) + kinetic energy (K.E)
This formula and the explanation above can be used to answer the completed question.
NOTE: There is no standard relationship between P.E and K.E. They could be directly or indirectly proportional depending on the circumstance.
Answer:
The number of moles =
The number of molecules =
Explanation:
Volume of the sphere is given by :
here, r = radius of the sphere
Radius = 3 mm
r = 3 mm
1 mm = 0.01 dm (1 millimeter = 0.001 decimeter)
3 mm = 3 x 0.01 dm = 0.03 dm
r = 0.03 dm
<em>("volume must be in dm^3 , this is the reason radius is changed into dm"</em>
<em>"this is done because 1 dm^3 = 1 liter and concentration is always measured in liters")</em>
(1 L = 1 dm3)
Now, concentration "C"=
The concentration is given by the formula :
This is also written as,
moles
One mole of the substance contain "Na"(= Avogadro number of molecules)
So, "n" mole of substance contain =( n x Na )
Molecules =
molecules
What is the difference between the two numbers? That is your answer
