<span>0.496 g of NaOH required
3 pellets.
First, determine the molar mass of NaOH.
Atomic weight sodium = 22.989769
Atomic weight hydrogen = 22.989769
Atomic weight oxygen = 15.999
Molar mass NaOH = 22.989769 + 22.989769 + 15.999 = 61.978538 g/mol
Now determine how many moles of NaOH we need. Multiply desired volume by desired molarity. So
0.200 l * 0.040 mol/l= 0.008 mol
To get the mass, then multiply by the molar mass, so
0.008 mol * 61.978538 g/mol = 0.495828304 g
Since we have the NaOH in pellet form, divide the desired mass by the mass of each pellet. So
0.495828304 g / 0.170 g/pellet = 2.916637082 pellets
You'll need 3 pellets.
To get closer to the desired molarity, I would recommend increasing the amount of solution being prepared if you can accurately measure the larger volume.</span>
Answer:
when it reduces heat.
Explanation:
Thermal energy is transferred to material,the motion of its particles speeds up and it's temperature differences.Insulating materials are bad conductors and so this reduces the heat loss by conduction.The material also prevents air circulating inside the cavity,therefore reducing heat loss by convection.Heat loss through the roof can be reduced by laying loft insulation.
It is the periodic table
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hi im breanna
Answer:
The mole is simply a very large number that is used by chemists as a unit of measurement.
Explanation:
The mole is simply a very large number,
6.022
×
10
23
, that has a special property. If I have
6.022
×
10
23
hydrogen atoms, I have a mass of 1 gram of hydrogen atoms . If I have
6.022
×
10
23
H
2
molecules, I have a mass of 2 gram of hydrogen molecules. If I have
6.022
×
10
23
C
atoms, I have (approximately!) 12 grams.
The mole is thus the link between the micro world of atoms and molecules, and the macro world of grams and litres, the which we can easily measure by mass or volume. The masses for a mole of each element are given on the periodic table as the atomic weight. So, if have 12 g of
C
, I know, fairly precisely, how many atoms of carbon I have. Given this quantity, I know how many molecules of
O
2
are required to react with the
C
, which I could measure by mass or by volume.