Answer:
1.51 x 10²⁴molecules
Explanation:
Given parameters:
Number of moles of NaCl = 2.5moles
Unknown:
Number of molecules = ?
Solution:
The number of molecules that can be found in a given mole is given as the Avogadro's constant;
1 mole of substance = 6.02 x 10²³ molecules
2.5 mole of NaCl = 2.5 x 6.02 x 10²³ molecules
= 1.51 x 10²⁴molecules
The dye molecules move in a directed way from high to low concentration
Explanation:
The statement that best describes the motion of dye molecule in water is directed from a region of high to low concentration. The motion of the particles of the dye in water is described as diffusion:
- diffusion is the movement of molecules of a substance from one position to another.
- diffusion occurs from a region of high concentration to that of a low concentration.
- the dye in the water solution causes an increase in concentration of an area where it is dropped.
- this causes the particles to spread outward in the solution.
- a concentration gradient is set up between the two parts of the solution.
- this gradient facilitates the movement of the dye particles.
Learn more:
diffusion brainly.com/question/6873289
#learnwithBrainly
Answer:
32 mL
Explanation:
<em>A chemist must prepare 500.0mL of hydrobromic acid solution with a pH of 0.50 at 25°C. He will do this in three steps: Fill a 500.0mL volumetric flask about halfway with distilled water. Measure out a small volume of concentrated (5.0M) stock hydrobromic acid solution and add it to the flask. Fill the flask to the mark with distilled water. Calculate the volume of concentrated hydrobromic acid that the chemist must measure out in the second step. Round your answer to 2 significant digits.</em>
<em />
Step 1: Calculate [H⁺] of the dilute solution
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -0.50 = 0.32 M
Step 2: Calculate [HBr] of the dilute solution
HBr is a strong acid that dissociates according to the following equation.
HBr ⇒ H⁺ + Br⁻
The molar ratio of HBr to H⁺ is 1:1. The concentration of HBr is 1/1 × 0.32 M = 0.32 M.
Step 3: Calculate the volume of the concentrated HBr solution
We will use the dilution rule.
C₁ × V₁ = C₂ × V₂
V₁ = C₂ × V₂ / C₁
V₁ = 0.32 M × 500.0 mL / 5.0 M
V₁ = 32 mL
Answer:
The periodic law states “When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties
