The difference between the initial mass (1.04 g) and the final mass (0.61g) is the mass of water present in the sample:
1.04 g - 0.61 g = 0.43 g
Divide by the molar mass of water: 18.01 g / mol to obtain the number of moles of water:
0.43 g / 18.01 g / mol = 0.0239 moles
Calculate the number of moles of dehydrated NiSO4
Number of moles = mass in grams / molar mass
molar mass of NiSO4 = 154.75 g/mol
number of moles NiSO4 = 0.61 g / 154.75 g/mol = 0.00394 moles
Now determine the molar ratio water to NiSO4: 0.0239 / 0.00394 = 6.07 ≈ 6
Then, the formula of the hydrate product is NiSO4 · 6 H2O.
Use the prefix hexa (6) to name the compound: Nickel(II) sulfate hexadydrate
This problem is providing us with two reactions between gold (III) chloride and cobalt in order to obtain the two possible cobalt chlorides and gold. Thus, it asks for the most feasible reaction, which is found to be the second one.
<h3>Uses of stoichiometry</h3>
In chemistry, relationships between moles and grams in chemical reactions can be studied via stoichiometry, which is based on proportional factors relating molar masses and mole ratios in chemical equations.
In this case, since we have two reactions and the same initial amount of cobalt, one can calculate the grams of solid gold, with the 1:1 mole ratio of these two in the first reaction and the 3:2 mole ratio in the second one and their atomic masses of 58.933 g/mol and 196.966 g/mol respectively:
Thus, since the second reaction would produce 13.56 grams of gold, and it is pretty much the same to the recovered amount of 13.572 grams, one concludes the second reaction took place in the experiment.
Learn more about stoichiometry: brainly.com/question/9743981
Answer:
C.) 1345.5 J
Explanation:
To find the energy, you need to use the following equation:
Q = mcΔT
In this equation,
-----> Q = energy (J)
-----> m = mass (g)
-----> c = specific heat (J/g°C)
-----> ΔT = change in temperature (°C)
The specific heat of aluminum is 0.89 J/g°C. You can plug the given values into the equation and solve.
Q = mcΔT
Q = (150 g)(0.89 J/g°C)(10 °C)
Q = 1335
*It is up to you whether you wish to trust this answer. My answer may be slightly different due to using a different specific heat.
Answer:
A. Controlled variable
Explanation:
a controlled variable or a constant variable is a variable that doesnt change during an experiment