Answer:
The pH is 2, 60
Explanation:
The pH gives us an idea of the acidity or basicity of a solution. It is calculated as:
pH = -log (H +)= -log (2.5x10-3 )
<em>pH=2, 60</em>
Answer:
3.01 × 10²⁴ atoms S
General Formulas and Concepts:
<u>Chemistry - Atomic Structure</u>
- Using Dimensional Analysis
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Explanation:
<u>Step 1: Define</u>
5.00 mol S
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
<u />
= 3.011 × 10²⁴ atoms S
<u />
<u>Step 4: Check</u>
<em>We are given 3 sig figs. Follow sig fig rules and round.</em>
3.011 × 10²⁴ atoms S ≈ 3.01 × 10²⁴ atoms S
Answer:
See below
Step-by-step explanation:
Matter is either a <em>pure substance</em> or a <em>mixture.
</em>
Pure substances
- Are composed of one type of atom or molecule.
- Have a constant chemical composition
- Have fixed chemical properties
- Have fixed physical properties
• For example, melting point, boiling point, density, solubility
Mixtures:
- Consist of two or more substances not chemically combined
- Have a variable composition
- Can be separated into two or more components by physical means
• For example, filtration, distillation, centrifugation
- Each component retains its own properties
<span>Pre-1982 definition of STP: 37 g/mol
Post-1982 definition of STP: 38 g/mol
This problem is somewhat ambiguous because the definition of STP changed in 1982. Prior to 1982, the definition was 273.15 K at a pressure of 1 atmosphere (101325 Pascals). Since 1982, the definition is 273.15 K at a pressure of exactly 100000 Pascals). Because of those 2 different definitions, the volume of 1 mole of gas is either 22.414 Liters (pre 1982 definition), or 22.71098 liters (post 1982 definition). And finally, there's entirely too many text books out there that still use the 35 year obsolete definition. So let's solve this problem using both definitions and you need to pick the correct answer for the text book you're using.
First, determine how many moles of gas you have. Just simply divide the volume you have by the molar volume.
Pre-1982: 2.1 / 22.414 = 0.093691443 moles
Post-1982: 2.1 / 22.71098 = 0.092466287 moles
Now determine the molar mass. Simply divide the mass by the moles. So
Pre-1982: 3.5 g / 0.093691443 moles = 37.35666667 g/mol
Post-1982: 3.5 g / 0.092466287 moles = 37.85163333 g/mol
Finally, round to 2 significant figures. So
Pre-1982: 37 g/mol
Post-1982: 38 g/mol</span>
Proton = +1
neutron = 0
electron = -1
