Answer:
Mar 29, 2015 · Their settlements are much more permanent and include houses, storage buildings, etc. They also need preservation methods and storage techniques, unlike the nomads. Sedentary Societies were first to be seen near waterways such as rivers.
Explanation:
The heat that is required to raise the temperature of an object is calculated through the equation,
heat = mass x specific heat x (T2 - T1)
Specific heat is therefore calculated through the equation below,
specific heat = heat / (mass x (T2 - T1))
Substituting,
specific heat = 645 J / ((28.4 g)(15.5 - - 11.6))
The value of specific heat from above equation is 0.838 J/g°C.
Answer:
The final temperature of the solution is 44.8 °C
Explanation:
assuming no heat loss to the surroundings, all the heat of solution (due to the dissolving process) is absorbed by the same solution and therefore:
Q dis + Q sol = 0
Using tables , can be found that the heat of solution of CaCl2 at 25°C (≈24.7 °C) is q dis= -83.3 KJ/mol . And the molecular weight is
M = 1*40 g/mol + 2* 35.45 g/mol = 110.9 g/mol
Q dis = q dis * n = q dis * m/M = -83.3 KJ/mol * 13.1 g/110.9 gr/mol = -9.84 KJ
Qdis= -9.84 KJ
Also Qsol = ms * Cs * (T - Ti)
therefore
ms * Cs * (T - Ti) + Qdis = 0
T= Ti - Qdis * (ms * Cs )^-1 =24.7 °C - (-9.84 KJ/mol)/[(104 g + 13.1 g)* 4.18 J/g°C] *1000 J/KJ
T= 44.8 °C
Answer:
1) single replacement
2) combustion reaction.
3) double replacement reaction
4) combination reaction
5) decomposition reaction
Explanation:
Chemical equation:
Fe₂CO₃ + 3C → 2Fe + 3CO
The given reaction is single replacement reaction. In this reaction carbon react with Fe₂CO₃ and replace the iron from CO₃²⁻ and form free iron and carbon monoxide.
Chemical equation:
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
The given reaction is combustion reaction. In which ethene burn in the presence of oxygen form carbon dioxide and water.
Chemical equation:
Fe₂O₃ + 6HCl → 2FeCl₃ + 3H₂O
The given reaction is double replacement reaction. In which anion and cation of both reactants exchange with each others.
Chemical equation:
2Al + 2Br₂ → 2AlBr₃
The given reaction is combination reaction in which aluminium and bromine combine to form aluminium bromide.
Chemical equation:
C₆H₁₂O₆ → 6C + 6H₂O
The given reaction is decomposition reaction in which glucose molecule decompose to give water and carbon.
