Density = mass/volume
From this equation we can also say:
Volume = mass/density
V = 2500.0g/10.5g/cm3
V = 238 cm3
Answer:
c 18.0ml
Explanation:
The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.
The correct answer is 42. I know this answer is right because i have already turned my assignment in and got it right.
The number of atoms of K that are in 235 g of the compound is
2.57 x10^24 atoms
calculation
Step 1: find the moles of K2S
= moles = mass/molar mass
= 235 g/110 g/mol= 2.136 moles
Step 2: multiply 2.136 moles by no. of K atoms in K2S
= 2.136 x2 = 4.272 moles
Step 3: use the Avogadro's law to determine number of K atoms
that is according to Avogadro's law 1 mole = 6.02 x 10^23 atoms
4.272 moles= ? atoms
by cross multiplication
= (4.272 moles x 6.02 x10^23 atoms) / 1 mole = 2.57 x10^24 atoms
