Answer:
2.5 g of platinum
Explanation:
A catalyst is a substance added to a reaction to enhance the reaction speed. It does not undergo any change during the reaction, meaning it remains unchanged after the reaction concludes. The role of a catalyst is to provide an alternative pathway for the reaction by reducing the activation energy required. Therefore, a catalyzed reaction occurs more rapidly and requires less energy compared to an uncatalyzed one.
Since catalysts do not get involved in reactions and retain their mass post-reaction, the amount of platinum will stay the same (2.5g). The mass can only alter if a substance participates in the chemical process. Thus, this is the response.
Answer:
Explanation:
Diethyl malonate possesses greater acidity compared to monocarbonyl substances (pKa=13) because its alpha hydrogens are linked to two carbonyl groups. Consequently, the malonic ester can be readily changed into its enolate ion by reacting it with sodium ethoxide in ethanol. When the malonic ester undergoes alkylation, a hydrogen atom in the alpha position becomes acidic, permitting another round of alkylation to yield a dialkylated malonic ester.
In this scenario, when diethyl malonate interacts with urea in the presence of sodium ethoxide base, the second alkylation step occurs within the molecule, producing a cyclic compound known as barbituric acid.
Solution:
Molality measures the concentration of a solute in a solution, defined by the amount of solute per specific mass of solvent.
Thus,
Molality = moles of solute / kg of solvent.
Therefore, kg of solvent = moles of solute / molality.
moles of solute = mass / molar mass
= 25.31 g / 101.1 g/mole
= 0.2503 mole.
kg of solvent = 0.2503 mole / 0.1982 m
= 1.263 kg
= 1263 g.
This is the final answer.
The element with atomic number 58 is Cerium, meaning its symbol should be Ce rather than Co, which belongs to Cobalt with atomic number 27. Therefore, the notation for isotopes consists of the element's symbol accompanied by a superscript and a subscript, properly aligned. The superscript indicates the mass number.
Mass number = protons + neutrons = 58 + 33 = 91
The subscript denotes the atomic number, which is 58. This notation is illustrated in the attached image.
Answer:
Chemists observe phenomena on a macroscopic level which informs their understanding of microscopic aspects.
Explanation:
Many critical chemical insights arise from macroscopic observations because most scientific instruments currently cannot directly evidence microscopic events. Data gathered from these larger-scale observations can yield valuable insights into the nature of specific microscopic interactions.
This is particularly true in atomic structure studies. The majority of evidence that contributed to our understanding of atomic structure was obtained from macroscopic observations and subsequently provided crucial information regarding the atom's microscopic configuration.
