Explanation:
Moles=mass/molar mass
moles × molar mass = mass
0.206 x 119= mass
Mass= 24. 51grams
The mass of water produced when 4.86 g of butane(C4H10) react with excess oxygen is calculated as below
calculate the moles of C4H10 used = mass/molar mass
moles = 4.86g/58 g/mol =0.0838 moles
write a balanced equation for reaction
2 C4H10 + 13 O2 = 8 CO2 + 10 H2O
by use of mole ratio between C4H10 to H2O which is 2:10 the moles of
H20= 0.0838 x10/2 = 0.419 moles of H2O
mass = moles x molar mass
=0.419 molx 18 g/mol = 7.542 grams of water is formed
Answer:
6.05 g
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
From the question ,
M = 200mM
Since,
1 mM = 10⁻³ M
M = 200 * 10⁻³ M
V = 250 mL
Since,
1 mL = 10⁻³ L
V = 250 * 10⁻³ L
The moles can be calculated , by using the above relation,
M = n / V
Putting the respective values ,
200 * 10⁻³ M = n / 250 * 10⁻³ L
n = 0.05 mol
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
m = 121 g/mol
n = 0.05 mol ( calculated above )
The mass of tri base can be calculated by using the above equation ,
n = w / m
Putting the respective values ,
0.05 mol = w / 121 g/mol
w = 0.05 mol * 121 g/mol
w = 6.05 g
they can find dna at the crime scene wich will lead them to the guilty party
Answer:
Sodium iodide NaI
Magnesium chloride MgCl₂
Explanation:
Silicon dioxide SiO₂ it is not soluble in water, so it can not be recrystallized from water, it is a white solid and the boiling point is 2230 °C. This one is not the unknown solid.
Sodium iodide NaI it is soluble in water, it has a white color and the boiling point is 1304 °C
. This can be the unknown solid.
Magnesium chloride MgCl₂ is soluble in water, it have a white color and the boiling point is 1,412 °C
. This can be the unknown solid.
Phosphorus tribromide PBr₃ is will start a hydrolysis reaction in water, it is a colorless liquid and it has a boiling point of 173 °C. This one is not the unknown solid.
