Answer:
Exothermic reaction for the HCl, endothermic reaction for the water
Explanation:
Heat was lost by HCl as its temperature lowered, so it was an exothermic reaction for the HCL.
Heat was gained by water as its temperature increased, so it was an endothermic reaction for the water.
m = Mass of water = 100 g
c = Specific heat of water = 
= Change in temperature of water = 
Heat is given by
Heat gained by water is .
Answer:
See the answer below
Explanation:
<em>Since the experiment is set out to determine the melting point of the white solid, after missing the melting point due to distraction, there are two possible solutions and both involves a repeat of the experiment.</em>
1. The first one is to allow the molten substance to solidify again and then repeat the experiment. This time around, a critical attention should be paid to be able to notice the melting point temperature once the temperature gets to 132 C.
2. The second solution would be discard the molten substance and repeat the experiment with the a new solid one. Similarly, critical attention should be paid once the temperature gets to 132 C since it is sure that the melting point lies within 132 and 138 C.
Answer:
<h2>Density = 8.96 g/cm³</h2>
Explanation:
The density of a substance can be found by using the formula
From the question
mass of copper = 89.6 g
volume = 10 cm³
Substitute the values into the above formula and solve
That's
We have the final answer as
<h3>Density = 8.96 g/cm³</h3>
Hope this helps you
Answer:
mass of CO = 210.42 g
mass in three significant figures = 210. g
Explanation:
Given data:
mass of Fe2O3 = 0.400 Kg
mass of CO= ?
Solution:
chemical equation:
Fe2O3 + 3CO → 2Fe + 3CO2
Now we will calculate the molar mass of Fe2O3 and CO.
Molar mass of Fe2O3 = (55.845 × 2) + (16 × 3) = 159.69 g/mol
Molar mass of CO = 12+ 16 = 28 g/mol
now we will convert the kg of Fe2O3 in g.
mass of Fe2O3 = 0.400 kg × 1000 = 400 g
number of moles of Fe2O3 = 400 g/ 159.69 g/mol = 2.505 mol
mass of CO = moles of Fe2O3 × 3( molar mass of CO)
mass of CO = 2.505 mol × 84 g/mol
mass of CO = 210.42 g
mass in three significant figures = 210. g
