Here is the complete question.
Benzalkonium Chloride Solution ------------> 250ml
Make solution such that when 10ml is diluted to a total volume of 1 liter a 1:200 is produced.
Sig: Dilute 10ml to a liter and apply to affected area twice daily
How many milliliters of a 17% benzalkonium chloride stock solution would be needed to prepare a liter of a 1:200 solution of benzalkonium chloride?
(A) 1700 mL
(B) 29.4 mL
(C) 17 mL
(D) 294 mL
Answer:
(B) 29.4 mL
Explanation:
1 L = 1000 mL
1:200 solution implies the 
in 200 mL solution.
200 mL of solution = 1g of Benzalkonium chloride
1000 mL will be 
200mL × 1g = 1000 mL × x(g)
x(g) = 
x(g) = 0.2 g
That is to say, 0.2 g of benzalkonium chloride in 1000mL of diluted solution of 1;200 is also the amount in 10mL of the stock solution to be prepared.
∴ 
y(g) = 
y(g) = 5g of benzalkonium chloride.
Now, at 17% concentrate contains 17g/100ml:
∴ the number of milliliters of a 17% benzalkonium chloride stock solution that is needed to prepare a liter of a 1:200 solution of benzalkonium chloride will be;
= 
z(mL) = 
z(mL) = 29.41176 mL
≅ 29.4 mL
Therefore, there are 29.4 mL of a 17% benzalkonium chloride stock solution that is required to prepare a liter of a 1:200 solution of benzalkonium chloride
The question is incomplete, complete question is:
When copper(I) sulfide is partially roasted in air (reaction with oxygen), copper(I) sulfite is formed first. subsequently, upon heating, the copper sulfite thermally decomposes to copper(I) oxide and sulfur dioxide. Write balanced chemical equations for these two reactions.
Answer:
The balanced chemical equations for these two reactions:
Explanation:
On partial roasting of copper sulfide in an air. The balanced chemical reaction is given as:
On further heating of copper(I) sulfite it get decomposes into copper oxide and sulfur dioxide. The balanced chemical reaction is given as:
I would have to say no. There are metamorphic rocks, igneous rocks, and sedimentary rocks. Igneous rocks are rocks that have solidified from magma or lava upon cooling, like lava rocks. Sedimentary rocks are rocks from smaller sediments, such as sandstone being made from, well, sand. Metamorphic rocks are the result of preexisting rocks in a response to changes in the environment. This includes changes in pressure, air temperature, mechanical stress, as well as taking away or adding chemical components. Metamorphic can be from igneous, sedimentary, or any other metamorphic rocks. Hopefully this help (with the added bonus that I explained all three type of rocks.
Answer: dispersion forces, dipole-dipole and hydrogen bonds
Explanation:
The term "pKa" is a measure of the strength of an acid in solution. It is defined as the negative base 10 log of the acid dissociation constant. A lower pKa value indicates a stronger acid and A higher pKa value indicates a weaker acid
