Answer:
D
Explanation:
The correct thing to do in this case would be to <u>repeat the experiment.</u>
The scientist would need to repeat the experiment in order to double-check the accuracy. If the accuracy is indeed doubtful, he/she can be able to trace the source of the error by repeating the experiment.
The correct option is D.
Answer:
the second one looks like it so I picked the second one
<h3>
Answer:</h3>
0.6 g NaCl
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Atomic Structure</u>
<u>Stoichiometry</u>
- Using Dimensional Analysis
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
[RxN - Balanced] Na₂CO₃ (aq) + CaCl₂ (aq) → CaCO₃ (s) + 2NaCl (aq)
[Given] 0.5 g Na₂CO₃ reacted with excess CaCl₂
<u>Step 2: Identify Conversions</u>
[RxN] Na₂CO₃ → 2NaCl
Molar Mass of Na - 22.99 g/mol
Molar Mass of C - 12.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Cl - 35.45 g/mol
Molar Mass of Na₂CO₃ - 2(22.99) + 12.01 + 3(16.00) = 105.99 g/mol
Molar Mass of NaCl - 22.99 + 35.45 = 58.44 g/mol
<u>Step 3: Stoichiometry</u>
- Set up:

- Multiply/Divide:

<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 1 sig fig.</em>
0.551373 g NaCl ≈ 0.6 g NaCl
Molarity is simply the ratio of the number of moles of a
substance over the total volume of the solution. Assuming that the addition of
0.850 moles does not change the overall volume of 1.70 L, therefore molarity is
simply:
Molarity = 0.850 moles / 1.70 L = 0.5 moles / L = 0.5 M
Answer:
The weights of all elements are always compared to the Carbon-12.
Explanation:
The weights of all elements are always compared to the Carbon-12 because the mass of carbon is 12 which is the exactly the sum of protons and neutrons.
Oxygen was also considered the standard for some time but later this stander was rejected because in natural O¹⁷ and O¹⁸ were also present and this create the two different atomic mass tables.
AMU:
Atomic mass unit is define as the 1/12 the mass of an atom of carbon-12.
C12 has six neutron and six protons in the nucleus.
This unit is used to express the masses of atoms. We know that masses of atoms are very small and we do not have any such type of balance that can measure very small quantity. So that is way we use this scale to measure small quantity. For example, according to this scale
relative atomic mass of hydrogen is 1.008 amu
relative atomic mass of oxygen is 15.999 amu
relative atomic mass of uranium is 238.0289 amu
relative atomic mass of chlorine is 35.453 amu