Answer:
709 (With sig figs)
Explanation:
Pressure(1) * volume(1) = Pressure(2) * volume(2)
771.75 mm Hg * unknown = 874.27 mm Hg * 626 mL
771.75 mm Hg * unknown = 547,293.02 mm Hg*mL
Divide both sides by 771.75 mm Hg
Unknown = 709 (With sig figs)....709.158432 (without sig figs)
This answer would be heat capacity
Answer:
calcium and gold
Explanation:
thats what it said was right
The correct answer is 96.80 grams
Explanation:
The density of a substance shows the total mass the substance contains in 1 mL or 1 cm3 as density is calculated by using the formula D= M (mass) / V (volume). This implies, Iron contains 7.87 grams per milliliter. Moreover, this value and formula can be used to calculate the mass or volume of any other sample. The process to calculate the mass of an iron sample with a volume of 12.3 mL is shown below.
D = M ÷ V
7.87 mL = x ÷ 12.3 mL - x represents the missing value. Now find the value of x by solving the equation
x = 7.87 · 12.3
x = 96.80
This means a sample of 12.3 mL contains a mass of 96.80 grams. Also, you can know this value is correct because if you divide the mass by the value the density is the same (96.80 grams ÷ 12.3 mL = 7.87 g/mL)
To know the number of atoms, it will be necessary to use the formula of avogadro. We calculate the number of moles then we can calculate the number of avogadro.
The molar mass of:
Phosphorus = 31g / mol
Mercury = 200 g / mol
Bismuth = 209 g / mol
Strontium = 87 g / mol.
The number of avogadro (N) is 6.023 10 ^ 23
n = m (mass) / M (molar mass)
number of atoms = n. N = m / M . N
number of phosphorus atoms = 5.14/31 . 6.023 10^23 = 9.98 10 ^ 22 atoms
Number of atoms of mercury = 2.16/200 . 6.023 10^23 = 6.5 10 ^ 21 atoms
Number of bismuth atoms = 1.8/209 . 6.023 10^23 = 5.18 10 ^ 21 atoms
Number of strontium atoms = 8.8 x 10-2 /87 . 6.023 10^23 = 6.09 10 ^ 20 atoms
