Answer:
14175 j heat released.
Explanation:
Given data:
Mass of aluminium = 350.0 g
Initial temperature = 70.0°C
Final temperature = 25.0°C
Specific heat capacity of Aluminium = 0.9 j/g.°C
Heat changed = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Heat change:
ΔT = Final temperature - initial temperature
ΔT = 25.0°C - 70°C
ΔT = -45°C
Q = m.c. ΔT
Q = 350 g × 0.9 j/g.°C × -45°C
Q = -14175 j
What do you want us to work out?
Answer: Eutrophication is the enhancement of the growth of algae in the water body.
Explanation:
The scientists are worried for the climate change as if the climate changed to prolonged rainy then the frequent raining can remove toxic chemicals from the agricultural sites, landfills, industries, and from other locations and deposit them to the water body (river, lakes, ponds, and others). The deposition of the salts of nitrogen, phosphorus, and sulfur promotes the growth of algae in the water body. This leads to reduction in the concentration of oxygen in the water body. This is called eutrophication. The lack of oxygen can lead to mortality of aquatic animals.
Answer:

Explanation:
The given reactions are:
PbCl2(aq)⇌Pb2+(aq)+2Cl−(aq) 
AgCl(aq)⇌Ag+(aq)+Cl−(aq) 
Required reaction is:
PbCl2(aq)+2Ag+(aq)⇌2AgCl(aq)+Pb2+(aq)

Answer:
0.098 moles
Explanation:
Let y represent the number of moles present
1 mole of Ba(OH)₂ contains 2 moles of OH- ions.
Hence, 0.049 moles of Ba(OH)2 contains y moles of OH- ions.
To get the y moles, we then do cross multiplication
1 mole * y mole = 2 moles * 0.049 mole
y mole = 2 * 0.049 / 1
y mole = 0.098 moles of OH- ions.
1 mole of OH- can neutralize 1 mole of H+
Therefore, 0.098 moles of HNO₃ are present.