Answer & Explanation:
In physics, a contact force is a force that acts at the point of contact between two objects, in contrast to body forces. Contact forces are described by Newton's laws of motion, as with all other forces in dynamics. Contact force is the force in which an object comes in contact with another object. Contact forces are also direct forces. Contact forces are ubiquitous and are responsible for most visible interactions between macroscopic collections of matter. Pushing a car up a hill or kicking a ball or pushing a desk across a room are some of the everyday examples where contact forces are at work. In the first case the force is continuously applied by the person on the car, while in the second case the force is delivered in a short impulse.
Answer:
There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids)
Explanation:
There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids), and each is an important component of the cell and performs a wide array of functions. ... Biological macromolecules are organic, meaning that they contain carbon.
Answer: The mass of electrons is mostly ignored because electrons are extremely small compared to neutrons and protons.
Explanation: A proton is about 1,836 times the size of an electron.
On the periodic table, the atomic number for each element can be found. This number is found by measuring the weight of 6.02 x 10^23 atoms of the element in grams. Electrons aren't ignored when finding exact math, but for the sake of simplification high school teachers will generally have you only count the number of protons and neutrons when calculating the mass of atoms.
Answer:
0.057 M
Explanation:
Step 1: Given data
Solubility product constant (Ksp) for HgBr₂: 2.8 × 10⁻⁴
Concentration of mercury (II) ion: 0.085 M
Step 2: Write the reaction for the solution of HgBr₂
HgBr₂(s) ⇄ Hg²⁺(aq) + 2 Br⁻
Step 3: Calculate the bromide concentration needed for a precipitate to occur
The Ksp is:
Ksp = 2.8 × 10⁻⁴ = [Hg²⁺] × [Br⁻]²
[Br⁻] = √(2.8 × 10⁻⁴/0.085) = 0.057 M
The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7
Given data :
mass of aspirin = 640 mg = 0.640 g
volume of water = 10 ounces = 0.295735 L
molar mass of aspirin = 180.16 g/mol
moles of aspirin = mass / molar mass = 0.00355 mol
<h3>Determine the pH of the solution </h3>
First step : <u>calculate the concentration of aspirin</u>
= moles of Aspirin / volume of water
= 0.00355 / 0.295735
= 0.012 M
Given that pKa of Aspirin = 3.5
pKa = -logKa
therefore ; Ka = 
= 
From the Ice table
= ![\frac{x + H^+}{[aspirin]}](https://tex.z-dn.net/?f=%5Cfrac%7Bx%20%2B%20H%5E%2B%7D%7B%5Baspirin%5D%7D)
= 
given that the value of Ka is small we will ignore -x
x² = 
x = 
Therefore
[ H⁺ ] =
given that
pH = - Log [ H⁺ ]
= - ( -3 + log 1.948 )
= 2.71 ≈ 2.7
Hence we can conclude that The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7
Learn more about Aspirin : brainly.com/question/2070753
