Answer:
Cu + HNO3 → Cu(NO3)2 + <u>H2O</u> + <u>NO2</u>
Cu + 4HNO3 → Cu(NO3)2 + <u>2H2O</u> + <u>2NO2 </u>(balanced equation)
Answer:- 3.84 grams
Solution:- Volume of the sample is 44.8 mL and the density is 1.03 gram per mL.
From the density and volume we calculate the mass as:
mass = volume*density

= 46.1 g
From given info, potassium bromide solution is 8.34% potassium bromide by mass. It means if we have 100 grams of the solution then 8.34 grams of potassium bromide is present in. We need to calculate how many grams of potassium bromide are present in 46.1 grams of the solution.
The calculations could easily be done using dimensional analysis as:

= 3.84 g KBr
Hence, 3.84 grams of KBr are present in 44.8 mL of the solution.
Answer:
A
Explanation:
Polypeptides such as proline and glycine are capable of making a sharp turn called a reverse turn due to the suitability and flexibility of their cyclic structure
Answer:
A
Explanation:
because number of particle = moles × 6.02 × 10^23
which gives the answer as an A
To calculate the pKa of the weak acid, we use the Henderson-Hasselbalch equation. It is expressed as pH = pKa - log [HA]/[A-]. This equation takes into account the concentration of the substance that does not dissociates into ions since it is a weak acid. We caculate as follows:
pH = pKa - log [HA]/[A-]
9 = pKa - log 1/100
pKa = 7