Answer:
Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.
Explanation:
Molarity of the solution is the moles of compound in 1 Liter solutions.
Mass of NaOH = x
Molar mass of NaOH = 40 g/mol
Volume of the NaOH solution = 450 mL =- 0.450 L ( 1 ml = 0.450 L)
Molarity of the solution of NaOH = 0.250 M
Solving for x:
x = 4.5 g
Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.
So if it is 2.35L at the temperature 20.0^C and you want the volume at -5.00^C this is hw you would solve it for example 20.0^C to 2.00L it would be 10 degrees per Liter so it would be here 10 degrees every liter so you would do 20.0 % 2.35 = / then find the answer and then find out how many degrees that answer is off of -5.00 then once you get that divide -5.00 with that answer.<span>
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Answer:
1. documenting, tinkering, testing
Explanation:
Technological design is defined as the process of study, design and development of new technologies.
There are some action in the methodical tests and refinements specific to technological design include documenting, tinkering, testing.
<u>Documenting </u><u>includes collecting all the information about the design and develop the product, </u><u>tinkering</u><u> involves repairing or adjust the issues found in the development, and </u><u>testing </u><u>helps to evaluate if the product is ready to work as it is supposed to.</u>
Hence, the correct answer is "1."
Answer:
(a) adding 0.050 mol of HCl
Explanation:
A buffer is defined as the mixture of a weak acid and its conjugate base -or vice versa-.
In the buffer:
1.0L × (0.10 mol / L) = 0.10 moles of HF -<em>Weak acid-</em>
1.0L × (0.050 mol / L) = 0.050 moles of NaF -<em>Conjugate base-</em>
-The weak acid reacts with bases as NaOH and the conjugate base reacts with acids as HCl-
Thus:
<em>(a) adding 0.050 mol of HCl:</em> The addition of 0.050moles of HCl produce the reaction of 0.050 moles of NaF producing HF. That means after the reaction, all NaF is consumed and you will have in solution just the weak acid <em>destroying the buffer</em>.
(b) adding 0.050 mol of NaOH: The NaOH reacts with HF producing more NaF. Would be consumed just 0.050 moles of HF -remaining 0.050 moles of HF-. Thus, the buffer <em>wouldn't be destroyed</em>.
(c) adding 0.050 mol of NaF: The addition of conjugate base <em>doesn't destroy the buffer</em>