Answer:
0.7g of HCl
Explanation:
First, let us write a balanced equation for the reaction between HCl and Al(OH)3.
This is illustrated below:
Al(OH)3 + 3HCl —> AlCl3 + 3H2O
Next, let us obtain the masses of Al(OH)3 and HCl that reacted together according to the equation. This can be achieved as shown below:
Molar Mass of Al(OH)3 = 27 + 3(16+1)
= 27 + 3(17) = 27 + 51 = 78g/mol.
Molar Mass of HCl = 1 + 35.5 = 36.5g/mol
Mass of HCl from the balanced equation = 3 x 36.5 = 109.5g
Now we can obtain the mass of HCl that would react with 0.5g of Al(OH)3. This can be achieved as follow:
Al(OH)3 + 3HCl —> AlCl3 + 3H2O
From the equation above,
78g of Al(OH)3 reacted with 109.5g of HCl.
Therefore, 0.5g of Al(OH)3 will react with = (0.5 x 109.5)/78 = 0.7g of HCl
Answer:
B) As you move across the row, the number of electrons increases and reactivity also increases.
Explanation:
The periodic table is arranged in a way that if you go across a period, the number of protons, neutrons, and electrons in an element increases. In terms of reactivity, the most reactive elements are the ones which have a high electronegativity. The electronegativity of the elements increases as you travel to the right and upwards on the periodic table.
The balanced reaction that describes the reaction of chlorine gas and sodium iodide to produce elemental iodine and sodium chloride in aqueous solution is expressed Cl2+2NaI= I2 + 2NaCl. This kind of reaction is called single replacement reaction where the anion, in this case, is only replaced
Answer: 70.0°C
Explanation:
Quantity of heat = Mass * Specific heat * Change in temperature
Quantity of heat = 104.6 KJ
Mass = 500.0 g
Specific heat of water is 4.18 J/g°C
Change in temperature assuming final temperature is x = x - 20
Units should be in grams and joules:
104,600 = 500 * 4.18 * (x - 20)
104,600 = 2,090 * (x - 20)
x - 20 = 104,600/2,090
x = 104,600/2,090 + 20
x = 69.8
= 70.0°C
Conservation of mass can be checked in an experiment . There are three steps to do it in a best way:
1. Weigh all the equipment and materials required in the experiment before the experiment.
2. Avoid spillage and evaporation during the experiment.
3. Weigh all the equipment and materials after the experiment.
If the mass is conserved then weight from step 1 is equal to weight from step 3.