Answer:
The final volume of NaOH solution is 30ml
Explanation:
We all know that
V1S1 = V2S2
or V1= V2S2÷S1
or V1= V2×S2×1/S1
or V1=100×0.15×1/0.50
V1= 30
∴30 ml NaOH solution is required to prepare 0.15 M from 100ml 0.50 M NaOH solution.
Answer:
Carbon
Explanation:
Micronutrients include elements or groups needed by the body in order to survive. These elements or groups include vitamins and minerals. Micronutrients can be divided into four categories:
1. water-soluble vitamins
2. Fat-soluble vitamins
3. Macrominerals
4. Trace minerals
Mình nghĩ C là đáp án đúng
Answer:
4.52 mol/kg
Explanation:
Given data:
Mass of lithium fluoride = 22.1 g
Mass of water = 188 g
Molality = ?
Solution:
Molality:
It is the number of moles of solute into kilogram of solvent.
Formula:
Molality = number of moles of solute / kilogram solvent
Mathematical expression:
m = n/kg
Now we will convert the grams of LiF into moles.
Number of moles = mass/ molar mass
Number of moles = 22.1 g/ 26 g/mol
Number of moles = 0.85 mol
Now we will convert the g of water into kg.
Mass of water = 188 g× 1kg/1000 g = 0.188 kg
Now we will put the values in formula.
m = 0.85 mol / 0.188 kg
m = 4.52 mol/kg
CH4 + 2 O2 ---> CO2 + 2 H2O Q = 891,6 kJ / mol CH4
1 mol CH4 = 16 g
16 g ---- 891,6 kJ
x g ----- 272 kJ
x = 272 kJ × 16 g / 891,6 kJ = 4,88 g
You must burn 4,88 g of CH4.
:-) ;-)
