Answer:
C. As scientists have learned more about chemicals, they have become more aware of their dangers
Explanation:
Chemicals are substances with standard compositions, held together by chemical bonds. Chemicals can exist in different phases such as solid, liquid, and gaseous phases. Over time, with a growing understanding of chemicals, their composition, and their reaction methods, scientists now have a better knowledge of the dangers chemicals can pose. To that effect, they have created standard safety measures for those who have to work with these chemicals.
When these guidelines are strictly adhered to, the chances of suffering accidents, burns, and explosions with these chemicals are significantly reduced.
It’s B. Chromium(III) oxide
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
