Answer:
(1)There are 1.5 moles of water in a 27 gram sample of water. The molar mass of water is 18.02 gmol g m o l .(2)
AnswersChemistryGCSEArticle
What is the mass (g) of 0.25mols of NaCl?
What you need for these equations are a calculator, periodic table and the following equation:
Mass (g) = Mr x Moles (important equation to remember)
In this case we already know the moles as it's in the question, 0.25 moles.
to find the Mr, you need to look at your periodic table. Find the relative atomic mass of Na and Cl and add the two numbers together.
Na = 22.99
Cl = 35.45
NaCl = 58.4
Now just put all of the numbers into the equation.
0.25 x 58.4 = 14.6g
738.1146 grams, your're welcome
Answer:
Polar covalent bond
Explanation:
On the basis of electronegativity bond could be ionic bond, polar and non pole covalent bond.
Ionic bond:
It is the bond which is formed by the transfer of electron from one atom to the atom of another element.
Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity. The electronegativity difference between bonded atoms is greater than 1.7.
For example:
Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion. Both atoms are bonded together electrostatic attraction occur between anion and cations.
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive. There are two type of covalent bond. Polar and non polar covalent bond. When electronegativity difference is 0.4 - 1.7 bond is polar covalent bond when it is less than 0.4 the bond is non polar covalent.
For example:
In CO the electronegativity of oxygen is 3.5 and carbon is 2.5. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and carbon becomes partial positive. and bond is polar covalent.
Answer: 
.
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of K = 49.4 g
Mass of S = 20.3 g
Mass of O = 30.3 g
Step 1 : convert given masses into moles.
Moles of K=
Moles of S= \frac{\text{ given mass of S}}{\text{ molar mass of S}}= \frac{20.3g}{32g/mole}=0.63moles[/tex]
Moles of O = \frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{30.3g}{16g/mole}=1.89moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For K = 
For S =
For O =
The ratio of K: S:O = 2: 1: 3
Hence the empirical formula is .
If they need 4 people to a pulley then they would need a 8 to two pulleys
here is the equation
4people*2/pulley*2
8people/2pulley
