To find the volume occupied by 2.0 g of CS₂ gas we can use the ideal gas law equation
PV = nRT
where P - pressure - 726 mmHg x 133 Pa/mmHg = 96 558 Pa
V - volume
n - number of moles = mass / molar mass
number of CS₂ moles = 2.0 g / 76.15 g/mol = 0.026 mol
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature in kelvin - 70 °C + 273 = 343 K
substituting these values in the equation
96 558 Pa x V = 0.026 mol x 8.314 Jmol⁻¹K⁻¹ x 343 K
V = 0.768 L
the volume occupied is 0.768 L
Answer:
340 grams Ca₃P₂ (2 sig. figs.)
Explanation:
3Ca + 2P => Ca₃P₂
5.6 mole + excess => ? grams
Convert the 'known' to a coefficient of 1 by dividing all coefficients by 3.
=> Ca + 2/3P => 1/3Ca₃P₂
From the above, 1 mole of Ca => 1/3 mole Ca₃P₂
∴ 5.6 mole Ca in an excess of P => 1/3(5.6 mole) Ca₃P₂
=> 1.8666 mol Ca₃P₂ (calculator answer) ≅ 1.9 mol Ca₃P₂
=> 1.9 mole x 182 g Ca₃P₂/mol Ca₃P₂ = 339.73333 grams Ca₃P₂
≅ 340 grams Ca₃P₂ (2 sig. figs.)
Answer:
Metals:
Copper: to make cooking utensils such as pots because it has a high heat conductivity.
Aluminium: to make aluminium foil / soda cans because it is malleable
Mercury: fills up thermometers because it can indicate the temperature when it expands. But it is toxic so fewer people are using mercury thermometers now.
Titanium: to make the body of supersonic aircrafts because it is strong and corrosion resistant
Gold: to make jewelry because it is shiny and also corrosion resistant
Non-metals:
Nitrogen: to fill up chip packages because its molecules are unreactive
Helium: to fill up balloons because it is lightweight
Hydrogen: for generating electricity in hydrogen fuel cells. It is environmentally-friendly because it does not produce any greenhouse gas or toxic pollutants.
Fluorine: added in toothpaste for strengthening the teeth. It can also prevent cavities.
Carbon: the graphite in pencils. this is one form of carbon. Other common forms (allotropes) of carbon include diamond and Buckminsterfullerene (buckyball).
