Answer:
12.19 hours prior to discovery was the corpse placed in the desert.
Explanation:
Heat required for fly eggs to develop into first instar larvae = 
From the given,
Exposure time = 16 hrs
Temperature = 27 C
The day time exposed hours is 10 hrs.-(7.00am-5.00pm)
So, the extra heat = 427.2-378= 49.2
The addition heat divided by average temperature.
Average temperature = 22.4 C
So, the total time exposed is night time hours to day time hours.
= 10+2.19 = 12.19 hrs.
Therefore, 12.19 hours prior to discovery was the corpse placed in the desert.
Answer:
NH4+(aq) → NH3(aq) + H+(aq)
Explanation:
Following arrhenius, an acid can be defined as:
An Arrhenius acid is a substance that, when added to water, increases the concentration of H+ ions in water.
NH4+(aq) → NH3(aq) + H+(aq)
The ammonium ion acts as a weak acid in aqueous solution, dissociating into ammonia and a hydrogen ion.
An Arrhenius base is a substance that, when added to water, increases the concentration of OH- ions in water.
NH4+(aq) will not dissciate in OH- ions. So it's not a base, but an acid.
6 Na + 1 Fe₂O₃ → 3 Na₂O + 6 Fe
<h3>Explanation</h3>
Method One: Refer to electron transfers.
Oxidation states:
- Na: from 0 to +1; loses one electron.
- Fe: from +3 to 0; gains three electrons.
Each mole of Fe₂O₃ contains two Fe atoms and will gain 2 × 3 = 6 electrons during the reaction. It takes 6 moles of Na to supply all those electrons.
6 Na + 1 Fe₂O₃ → ? Na₂O + ? Fe
- There are two moles of Na atoms in each mole of Na₂O. 6 moles of Na will make 3 moles of Na₂O.
- There are two moles of Fe atoms in each mole of Fe₂O₃. 1 mole of Fe₂O₃ will make 2 moles of Fe.
6 Na + 1 Fe₂O₃ → 3 Na₂O + 2 Fe
Method Two: Atoms conserve.
Fe₂O₃ has the largest number of atoms among one mole of all four species in this reaction. Assume <em>one</em> as its coefficient.
? Na + <em>1</em> Fe₂O₃ → ? Na₂O + ? Fe
There are two moles of Fe atoms and three moles of O atoms in each mol of Fe₂O₃. One mole of Fe₂O₃ contains two moles of Fe and three moles of O. There are one mole of O atom in every mole of Na₂O. Three moles of O will go to three moles of Na₂O.
? Na + <em>1</em> Fe₂O₃ → <em>3</em> Na₂O + <em>2</em> Fe
Each mole of Na₂O contains two moles of Na. Three moles of Na₂O will contain six moles of Na.
<em>6</em> Na + <em>1</em> Fe₂O₃ → <em>3</em> Na₂O + <em>2</em> Fe
Simplify the coefficients. All coefficients in this equation are now full number and relatively prime. Hence the equation is balanced.
6 Na + 1 Fe₂O₃ → 3 Na₂O + 2 Fe
Answer:
Explanation: Mendeleev arranged the elements on the basis of their atomic mass. Melting and boiling point were used as the physical characteristics in deciding the position of elements. He arranged the elements and wrote the formula of their oxides and hydrides which seemed to possess same chemical formula.
Explanation:
Tabulations of chemical elements differing in their organization from the traditional seen periodic system
