Answer: 22 kJ amount of energy is released in the following reaction.
Explanation: There are two types of reaction on the basis of amount of heat absorbed or released.
1. Endothermic reactions: These are the type of reactions in which reactants absorb heat to form the products. The energy of the reactants is less than the energy of the products.
2. Exothermic reactions: These are the type of reactions in which heat is released from the chemical reactions. The energy of the products is less than the reactants.
Sign convention for 
: This value is negative for exothermic reactions and positive for endothermic reactions.
For the given chemical reaction,
Energy of the products is less than the energy of the reactants, Hence, this reaction will be a type of exothermic reaction and energy will be released during this chemical change.
Amount of energy released = (350 - 372) kJ = -22kJ
Negative sign symbolizes the energy is being released. So, 22 kJ amount of energy is released in the following reaction.
Answer:
Explanation:
Density is found by dividing the mass by the volume.
The mass of the liquid is 12.7 grams.
We know that 15 mL of this liquid was added to a 50 mL graduated cylinder. Therefore, the volume is 15 mL. The 50 mL is not relevant, it only tells us about the graduated cylinder.
Substitute the values into the formula.
Divide.
Round to the nearest hundredth. The 6 in the tenth place tells us to round the 4 to a 5.
The density of the liquid is about 0.85 grams per milliliter and choice A is correct.
In comparison with liquids and gases, solids are more dense. The answer is letter B. <span>The
solid has a more definite shape and volume. The particles are locked into
place. It cannot be further compressed due to the bond that exists between the
molecules. The kinetic energy of the molecules is close to none because the
molecules are so close and so compact with each other. </span>
Answer: Transition from X to Y will have greater energy difference.
Explanation: For studying the energy difference, we require Planck's equation.
where, h = Planck's Constant
c = Speed of light
E = Energy
= Wavelength of particle
From the equation, it is visible that the energy and wavelength follow inverse relation which means that with low wavelength value, energy will be the highest and vice-versa.
As electron A falls from X-energy level to Y-energy level, it releases blue light which has low wavelength value (around 470 nm) which means that it has high energy.
Similarly, Electron B releases red light when it falls from Y-energy level to Z-energy level, which has high wavelength value (around 700 nm), giving it a low energy value.
Energy Difference between X-energy level and Y-energy level will be more.
The formula for pH given the pKa and the concentrations
are:
pH = pKa + log [a–]/[ha]
<span>
Therefore calculating:</span>
3.75 = 3.75 + log [a–]/[ha]
log [a–]/[ha] = 0
[a–]/[ha] = 10^0
<span>[a–]/[ha] = 1</span>
