Answer:
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
Explanation:
Let's consider the complete ionic equation between the ions present. It includes all the ions and the insoluble compounds (Fe₃(PO₄)₂ is insoluble).
Na⁺(aq) + 2 PO₄³⁻(aq) + 3 Fe²⁺(aq) + NO₃⁻(aq) ⇒ Fe₃(PO₄)₂ + Na⁺(aq) + NO₃⁻(aq)
The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble compounds.
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
<span>4000 kilogram/cubic meter
http://www.calculator.net/density-calculator.html?cdensity=&cdensityunit=kilogram%2Fcubic+meter&cvol...
</span>
Answer: norfenefrine 
Explanation:
Depression in freezing point is given by:
= Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte)
= freezing point constant = 
m= molality
Weight of solvent (ethanol)= 
Molar mass of unknown non electrolyte = M g/mol
Mass of unknown non electrolyte added = 82 mg = 0.082 g (1g=1000mg)
The molecular mass of norfenefrine is near to 154 and thus the identity of the white powder is norfenefrine .
The only option that fits is the last one — improper and biased measurements.
A scientist should be able to estimate a measurement to a tenth of the smallest scale division. The millimetre ruler would give an uncertainty of ±0.1 mm. The inch ruler would give an uncertainty of ±0.1 in. Since 1 in = 25.4 mm, 0.1 in = 2.54 mm. Thus, the <em>millimetre ruler is more precise</em> than the inch ruler.
Converting units <em>does not</em> change the degree of precision of a measurement.
The first scientist <em>did not</em> convert the units (the second scientist did!).
BUT, having different team members make the observations could introduce uncertainties caused by improper or biased readings of the equipment.
B) They worries people would destroy the animals and land.
