We assume that the stated 50% is measured by volume. Molarity defines the concentration in terms of moles of solute per volume of solution.
To find the moles of NaOH, use: (0.1 moles / L)(0.4 L)
n = 0.04 moles of NaOH
Assuming we start with 1 mL of 50% NaOH solution,
(1 mL solution)(1.525 g/mL)(0.50) = 0.7625 g
Then, the number of moles calculates as follows,[
0.7625 g NaOH x (1 mol / 40 g) = 0.01906 moles of NaOH
The volume of solution required can be determined by:(0.04 moles of NaOH)(1 mL solution / 0.01906 moles of NaOH)
Thus, the needed volume comes out to be 2.09 mL
Answer: 2.09 mL
<span>Reaksi antara besi dan asam klorida menghasilkan besi (II) klorida serta gas hidrogen.</span>
To tackle this problem, one must first determine the specific heat of water, which is the energy required to raise the temperature of 1 g of water by 1 degree C. The relationship is given by the formula q = c X m X delta T, where q indicates the specific heat of water, m signifies the mass, and delta T denotes the temperature change. The specific heat of water is 4.184 J/(g X degree C). The temperature of the water increased by 20 degrees, therefore: 4.184 x 713 x 20.0 = 59700 J, rounded to 3 significant digits, equals 59.7 kJ. This value indicates the energy required to produce B2O3 from 1 gram of boron. To convert this to kJ/mole, additional calculations are required. The gram atomic mass of Boron is 10.811, so dividing 1 gram of boron by 10.811 results in.0925 moles of boron. Given that 2 moles of boron are needed for the formation of 1 mole of B2O3, dividing the moles of boron by two yields.0925/2 =.0462 moles. Consequently, dividing the energy in KJ by the number of moles provides KJ/mole: 59.7/.0462 = 1290 KJ/mole.
Refer to the attached image. This does not depict the polymerization reaction of salicylic acid. It merely illustrates the structure of salicylic acid and what it looks like post-polymerization. The polymerization occurs through the linking of salicylic acid molecules, resulting in the formation of one water molecule.
Answer: The enthalpy change for the reaction is, 201.9 kJ
Explanation:
Based on Hess’s law of constant heat summation, the energy released or absorbed in a chemical reaction stays constant, regardless of whether the process unfolds in one step or multiple steps.
This principle implies, that chemical equations can be treated analogously to algebraic expressions, allowing addition or subtraction to create the needed equation. Thus, the overall enthalpy change corresponds to the summation of the individual enthalpy changes of the reactions occurring in between.
The balanced equation for 
appears as follows,
The intermediate balanced reactions are outlined as follows,
(1) 
(2) 
(3) 
(4) 
Next, we will multiply the first reaction by 2, reverse the second, and reverse and halve the third and fourth reactions before combining them. This gives us:
(1) 
(2) 
(3) 
(4) 
Therefore, the expression for the enthalpy of the reaction is,
Hence, the enthalpy change for this reaction is, 201.9 kJ
