Answer:
Nitrate from agriculture is now the most common chemical contaminant in the world’s groundwater aquifers. Aquatic ecosystems are affected by agricultural pollution; for example, eutrophication caused by the accumulation of nutrients in lakes and coastal waters impacts biodiversity and fisheries.
Absolute zero is the temperature at which the motion of particles that constitute heat will be minimal. The answer is A. It is the lowest temperature that is theoretically possible. It is zero on the kelvin scale, but equivalent to -273.15°C. Hope i helped.
Answer is: mass of the ore is 8.54kg.<span>
</span>ω(Ca₃(PO₄)₂ - calcium phosphate) = 58.6% ÷ 100% = 0.586.
m(P) = 1.00 kg · 1000 g/kg.
m(P) = 1000 g.
In one molecule of calcium phosphate there are two phosphorus atoms:
M(Ca₃(PO₄)₂) = 310.18 g/mol.
M(P) = 30.97 g/mol.
For one kilogram of phosphorus, we need:
M(Ca₃(PO₄)₂) : 2M(P) = m(Ca₃(PO₄)₂) : m(P).
310.18 g/mol : 61.94 g/mol = m(Ca₃(PO₄)₂) : 1000 g.
m(Ca₃(PO₄)₂) = 5007.75 g ÷ 1000 g/kg = 5.007 kg.
Mass of ore find from proportion:
m(Ca₃(PO₄)₂) : m(ore) = 56% : 100%.
m(ore) = 100% · 5.007 kg ÷ 58.6%.
m(ore) = 8.54kg.
