Answer: either B, or D
Explanation:
because one of those are the answer
Hydrogen is the smallest chemical element because it consists of only one proton in its nucleus. Its symbol is H, and its atomic number is 1 .It has an average atomic weight of 1.0079 amu, making it the lightest element.
a.1.00784 u
b.Atomic-36
Kr
Krypton
Atomic Weight. 83.80
That means that there must be a balance between the positively charged protons and the negatively charged electrons. Atoms must have equal numbers of protons and electrons. In our example, an atom of krypton must contain 36 electrons since it contains 36 protons. Electrons are arranged around atoms in a special way.
I think Both protons and neutrons (and their anti-particles) froze out at 1013 K, about 0.0001 seconds after the Big Bang. Protons and neutrons are sub atomic particles of an atom that are found in the nucleus of an atom. Proton is the positively charge particle while the neutron has no charge. The proton positive charge accounts for the positive nuclear charge.
The concentration required to begin to precipitate PbCl2 for PbCl2 is 0.0216 M.
<h3>
What is molarity?</h3>
Molarity is the measure of the concentration of any solute in per unit volume of the solution.
The reaction is 
The molarity of lead is 0.025 M
The ksp is given 17×10⁻⁵
Now, calculating the concentration
![[Pb^2^+] = 0.025 M.\\Ksp = 1.17 \times 10^-^5\\Ksp = [Pb^2^+] \times [Cl^-]^2\\[Cl^-] = \dfrac{\sqrt{ Ksp}}{[Pb^2^+]} \\\\[Cl^-] = \dfrac{\sqrt{ 0.0000117}}{0.025} \\[Cl^-] = 2.16 \times 10^-^2M.](https://tex.z-dn.net/?f=%5BPb%5E2%5E%2B%5D%20%3D%200.025%20M.%5C%5CKsp%20%3D%201.17%20%5Ctimes%2010%5E-%5E5%5C%5CKsp%20%3D%20%5BPb%5E2%5E%2B%5D%20%5Ctimes%20%20%5BCl%5E-%5D%5E2%5C%5C%5BCl%5E-%5D%20%3D%20%20%5Cdfrac%7B%5Csqrt%7B%20Ksp%7D%7D%7B%5BPb%5E2%5E%2B%5D%7D%20%5C%5C%5C%5C%5BCl%5E-%5D%20%3D%20%20%5Cdfrac%7B%5Csqrt%7B%200.0000117%7D%7D%7B0.025%7D%20%20%5C%5C%5BCl%5E-%5D%20%3D%202.16%20%5Ctimes%2010%5E-%5E2M.)
Thus, the concentration required to begin to precipitate PbCl2 for PbCl2 is 0.0216 M.
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Answer:
166 g/mol
Explanation:
Step 1: Write the neutralization reaction
H₂A + 2 NaOH ⇒ Na₂A + 2 H₂O
Step 2: Calculate the reacting moles of NaOH
48.3 mL of 0.0700 M NaOH react.
0.0483 L × 0.0700 mol/L = 3.38 × 10⁻³ mol
Step 3: Calculate the reacting moles of H₂A
The molar ratio of H₂A to NaOH is 1:2. The reacting moles of H₂A are 1/2 × 3.38 × 10⁻³ mol = 1.69 × 10⁻³ mol.
Step 4: Calculate the molar mass of H₂A
1.69 × 10⁻³ moles of H₂A have a mass of 0.281 g. The molar mass of H₂A is:
M = 0.281 g / 1.69 × 10⁻³ mol = 166 g/mol
