Chemical<span> reactions takes place in plants and animals, this result in the formation of substances in some plants and animals that can be used to treat illness. </span>Chemistry<span>is </span>important<span> to everyday </span>life<span>, because it provides medicine. The food we consume each day comes directly from </span>chemical<span> processes.</span>
The volume did not change, it remained at 20 ml
<h3>Further explanation</h3>
Given
20 ml a sample gas at STP(273 K, 1 atm)
T₂=546 K
P₂=2 atm
Required
The volume
Solution
Combined gas Law :
Input the value :
The volume does not change because the pressure and temperature are increased by the same ratio as the initial conditions (to 2x)
C. single replacement. A single replacement is represented by this formula : AB + C = AC + B
The answer is
b) electron
Answer:
Mass percentage → 0.074 %
[F⁻] = 741 ppm
Explanation:
Aqueous solution of flouride → [F⁻] = 0.0390 M
It means that in 1L of solution, we have 0.0390 moles of F⁻
We need the mass of solution and the mass of 0.0390 moles of F⁻
Mass of solution can be determined by density:
1g/mL = Mass of solution / 1000 mL
Note: 1L = 1000mL
Mass of solution: 1000 g
Moles of F⁻ → 0.0390 moles . 19g /1 mol = 0.741 g
Mass percentage → (Mass of solute / Mass of solution) . 100
(0.741 g / 1000 g) . 100 = 0.074 %
Ppm = mass of solute . 10⁶ / mass of solution (mg/kg)
0.741 g . 1000 mg/1g = 741 mg
1000 g . 1 kg/1000 g = 1kg
741 mg/1kg = 741 ppm
