Answer:
d. The formation of a covalent bond between two amino acids
Explanation:
In a chemical reaction, a substance transforms into another with different chemical properties and a different formula. Bonds are created and/or destroyed. It must obey the law of conservation of mass and the law of conservation of elements.
<em>Which of the following is a chemical reaction?</em>
<em>a. Making a hydrogen bond between a water molecule and a sugar molecule. </em>NO. This is a physical change in which sugar dissolves in water but both their chemical identities remain the same. The hydrogen bond is a force of attraction and not a real bond in which electrons are gained, lost or shared.
<em>b. The melting of ice.</em> NO. This is a physical change. Solid water turns into liquid water but the identity of the molecules is the same.
<em>c. Changing a carbon atom to a nitrogen atom by radioactive decay.</em> NO. This is a nuclear reaction in which a new element appears but it is not a chemical reaction because it does not fulfill the law of conservation of elements.
<em>d. The formation of a covalent bond between two amino acids.</em> YES. A new bond is created and a protein dimer is formed.
Answer:
191.6 g of CaCl₂.
Explanation:
What is given?
Mass of HCl = 125.9 g.
Molar mass of CaCl₂ = 110.8 g/mol.
Molar mass of HCl = 36.4 g/mol.
Step-by-step solution:
First, we have to state the chemical equation. Ca(OH)₂ react with HCl to produce CaCl₂:
Now, let's convert 125.9 g of HCl to moles using the given molar mass (remember that the molar mass of a compound can be found using the periodic table). The conversion will look like this:
Let's find how many moles of CaCl₂ are being produced by 3.459 moles of HCl. You can see in the chemical equation that 2 moles of HCl reacted with excess Ca(OH)₂ produces 1 mol of CaCl₂, so we state a rule of three and the calculation is:
The final step is to find the mass of CaCl₂ using the molar mass of CaCl₂. This conversion will look like this:
The answer would be that we're producing a mass of 191.6 g of CaCl₂.
The pH levels of acid rain are very acidic; in the range of 2.0-3.0, is not true for acid rain.
Answer: D
Explanation
Acid rain is termed for the rain which contains acidic precipitations.
The precipitations of acids are generally made up of sulfuring and nitric acid.
The sulfuric and nitric acids were formed by the chemical reaction occurring between the water, oxygen and other chemicals present in the atmosphere with the sulfur-di-oxide and nitrous oxide emitted in the atmosphere due to burning of natural resources, fossil fuels, etc.
The chemical reaction of these oxides with water, oxygen and other chemicals leads to formation of acids.
Some of the oxides are emitted from burning of natural resources while the major emissions occur from burning of fossil fuels.
Also the oxides react in atmosphere to form acids.
So the options (A),(B) and (C) are true for acid rain.
But the option (D) is not true as the acid rain is not much acidic in nature, as it is getting dissolved in water so the range of acidity is 4.2-4.4 and not 2.0-3.0.
Answer:
<h2>put the bigger number on top then add </h2>
Explanation:
41.369
