Answer:
number of moles of water (n) = 1.383 x10 ⁻⁵ mol
Explanation:
Data Given:
No. of molecules of water = 8.33×10¹⁸
No. of Mole of water = ?
Formula Used to calculate
no. of moles = numbers of particles (ions, molecules, atoms) /Avogadro's number
Avogadro's no. = 6.023 x10²³
So the formula could be written as
no. of moles (n) = no. of molecules of water /6.023 x10²³
Put the values in above formula
no. of moles (n) = 8.33×10¹⁸ /6.023 x10²³
no. of moles (n) = 8.33×10¹⁸ /6.023 x10²³
no. of moles (n) = 1.383 x10 ⁻⁵
so 1.383 x10 ⁻⁵ moles of water are represented by 8.33×10¹⁸ molecules of water.
Answer:
Group 1: alkali metals, or lithium family.
Group 2: alkaline earth metals, or beryllium family.
Group 3: the scandium family.
Group 4: the titanium family.
Group 5: the vanadium family.
Group 6: the chromium family.
Explanation:
Caesium -bluish(Latin) Chlorine -yellow/green (Greek) Iodine -violet (Greek) <span>Rhodium -rose (Greek) Sulphur - yellow (Arabic)</span>
In an average mass, each entry has equal weight. In a weighted average, we multiply each entry by a number representing its relative importance.
Assume that your class consists of 15 girls and 5 boys. Each girl has a mass of 54 kg, and each boy has a mass of 62 kg.
<em>Average mass</em> = (girl + boy)/2 = (54 kg + 62 kg)/2 = <em>58 kg</em>
<em>Weighted average (Method 1)
</em>
Use the <em>numbers of each</em> gender (15 girls + 5 boys)
,
Weighted average = (15×54 kg + 5×62 kg)/20 = (810 kg + 310 kg)/20
= 1120 kg/20 = <em>56 kg</em>.
If you put all the students on one giant balance, their total mass would be
1120 kg and the average mass of a student would be <em>56 kg.
</em>
<em>Weighted average (Method 2)
</em>
Use the <em>relative percentages</em> of each gender (75 % girls and 25 % boys).
Weighted average = 0.75×54 kg + 0.25×62 kg = 40.5 kg + 15.5 kg = <em>56 kg</em>
Each girl contributes 40.5 kg and each boy contributes 15.5 kg to the <em>weighted average</em> mass of a student.
In order to determine the formula of the hydrate, [Anhydrous Solid⋅xH2O], the number of moles of water per mole of anhydrous solid (x) will be calculated by dividing the number of moles of water by the number of moles of the anhydrous solid (Equation 2.12.
