Answer:
Final Temperature = 28.2 oC
Explanation:
Information given;
Mass of Iron = 20.8g
Initial Temperature of Iron = 100C
Mass of water = 55.3g
Initial temperature of water = 25.3 C
The presence of a coffee cup calorimeter hints that there is no heat loss to the surrounding and that the iron and water are at thermal equilibrium.
Thermal equilibrium means that there is no heat transfer going on between the bodies, which simply means that the bodies are at the same temperature.
Hence, both bodies would the same final temperature (T2)
H = M * C * ΔT (For iron)
H = 20.8 * 0.449 * ( 100 - T2)
H = 9.3392 ( 100 - T2)
H = 933.92 - 9.3392T2
H = M * C * ΔT (For water)
H = 55.3 * 4.184 * (T2 - 25.3)
H = 231.3752 (T2 - 25.3)
H = 231.3752T2 - 5853.79
Since they are in thermal equilibrium it means H (Iron) = H (water).
This leads to;
933.92 - 9.3392T2 = 231.3752T2 - 5853.79
231.3752T2 + 9.3392T2 = 5853.79 + 933.92
240.7144 T2 = 6787.71
T2 = 28.2 oC
Answer:
2
Explanation:
The 1 & 2 are both signifigant becuase they are presented in scientific notation.
Answer:b.CaCl2
Explanation:
A compound is a substance resulting when two or more elements are are chemically bonded together either ionically or covalently in a fixed ratio.
From the given options we can see that the only compound there is CaCl2 which is an ionic compound in the fixed ratio of one calcium ion to two chloride ions.
Other options , Cu,Na and Nd are merely pure substance---Elements
We are given with the following pairs:
<span>carbon and oxygen
hydrogen and helium
gold and silver
and we are asked if there is a pair that will produce the same spectrum. The answer is
</span>No two elements produce the same spectrum.This is because a light spectrum is unique to each element.
Unit of M is also mole/L, where mole is the moles of solute and L is the volume of the solution. The latter is given: 158 mL or 0.158 L. So we need to find out the moles of NH4Br.
Moles of NH4Br = Mass of NH4Br/molar mass of NH4Br = 17.0g/(14+1*4+79.9)g/mol = 0.1736 mole.
So, the molarity of the solution = 0.1736mole/0.158L = 1.10 mole/L = 1.10 M
