All matter is made of atoms.
Atoms bond together in certain ways.
Carbon atoms have a specific mass.
Answer:
The correct options are:
1) Pure chemical substance
2) Element.
Explanation:
each of the term is explained below:
1) <u>Mixture: </u> Since tungsten is an element in periodic table thus it is not a mixture.
2) False by definition of mixture.
3) false by definition of mixture.
4) <u>Solution:</u> Tungsten in a filament is in solid form hence solution is incorrect.
5) Since it is given in the question itself that the sample is pure hence option 'E' is correct as chemical substance is a pure substance that has a homogeneous composition and the sample in the question is given as pure.
6) <u>Compound:</u> By definition of compound it is formed by mixing 2 or more elements but since tungsten is an element that occurs independently in nature hence it is not a compound.
7) Tungsten is a element in the periodic table with atomic number 74.
The balanced equation given is:
4NH3 + 3O2 .....> 2N2 + 6H2O
From this equation, we can note that 4 moles of NH3 are required to produce 2 moles of N2.
Therefore, the mole ratio of NH3 to N2 is 4:2 which can be simplified into 2:1
The element used in advertising signs is neon.
Answer:
Cu(OH)₂ will precipitate first, with [OH⁻] = 2.97x10⁻¹⁰ M
Explanation:
The equilibriums that take place are:
Cu⁺² + 2OH⁻ ↔ Cu(OH)₂(s) ksp = 2.2x10⁻²⁰ = [Cu⁺²]*[OH⁻]²
Co⁺² + 2OH⁻ ↔ Co(OH)₂(s) ksp = 1.3x10⁻¹⁵ = [Co⁺²]*[OH⁻]²
Keep in mind that <em>the concentration of each ion is halved </em>because of the dilution when mixing the solutions.
For Cu⁺²:
2.2x10⁻²⁰ = [Cu⁺²]*[OH⁻]²
2.2x10⁻²⁰ = 0.25 M*[OH⁻]²
[OH⁻] = 2.97x10⁻¹⁰ M
For Co⁺²:
1.3x10⁻¹⁵ = [Co⁺²]*[OH⁻]²
1.3x10⁻¹⁵ = 0.25 M*[OH⁻]²
[OH⁻] = 7.21x10⁻⁸ M
<u>Because Copper requires less concentration of OH⁻ than Cobalt</u>, Cu(OH)₂ will precipitate first, with [OH⁻] = 2.97x10⁻¹⁰ M
