<span> the number of protons and neutrons in the nucleus of an </span><span>atom</span>
Answer:
9.0 g
Explanation:
There is some info missing. I think this is the original question.
<em>A chemist must prepare 0.9 L of sodium hydroxide solution with a pH of 13.40 at 25°C. He will do this in three steps: Fill a volumetric flask about halfway with distilled water. Weigh out a small amount of solid sodium hydroxide and add it to the flask. Fill the flask to the mark with distilled water. Calculate the mass of sodium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits.</em>
<em />
Step 1: Calculate the pOH
We use the following expression.
pH + pOH = 14.00
pOH = 14.00 - pH = 14.00 - 13.40 = 0.60
Step 2: Calculate [OH⁻]
We use the following expression.
pOH = -log [OH⁻]
[OH⁻] = antilog -pOH = antilog -0.60 = 0.25 M
Step 3: Calculate [NaOH]
NaOH is a strong base that releases 1 OH⁻. Then, [NaOH] = 0.25 M
Step 4: Calculate the mass of NaOH
The molar mass of NaOH is 40.00 g/mol. The mass required to prepare 0.9 L of a 0.25 M solution is:
Answer:
lightning candel is not a physical change.
when you light the candel the wax gets melted which cannot be reversed.
as physical change is that change in which no new substances are formed abd is reversible.
In the option above shattering the plate doesnot make any chemical change likewise cutting hair also doesnot mean so, and boiling water can be condensed.
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Answer:
Susie cooked sausages on a barbecue. (a) Fat and water in the sausages changed state. Draw one line from each statement to the correct change of state.
Explanation:
brailest/ crown please
Answer:27,430J/g.K
Explanation:q= mass* specific heat capacity * change in temperature (kelvin)
22*4.184*[(100-25) + 273]
22*4.184*298
27,430J/g.K