Answer:
Measuring the mass of metal used in a reaction
Explanation:
A quantitative observation is one in which you use numbers to measure a property.
You would use numbers to record the mass of a metal, e.g., 1 g.
You would use words to describe the colour of a solid, the feel of a liquid, and the niceness of an odour.
We are given with the following pairs:
<span>carbon and oxygen
hydrogen and helium
gold and silver
and we are asked if there is a pair that will produce the same spectrum. The answer is
</span>No two elements produce the same spectrum.This is because a light spectrum is unique to each element.
Answer: D and A
Explanation: just took the test
For equal moles of gas, temperature can be calculated from ideal gas equation as follows:
P×V=n×R×T ...... (1)
Initial volume, temperature and pressure of gas is 3.25 L, 297.5 K and 2.4 atm respectively.
2.4 atm ×3.25 L=n×R×297.5 K
Rearranging,
n\times R=0.0262 atm L/K
Similarly at final pressure and volume from equation (1),
1.5 atm ×4.25 L=n×R×T
Putting the value of n×R in above equation,
1.5 atm ×4.25 L=0.0262 (atm L/K)×T
Thus, T=243.32 K
If you have 8.51x10-3 g of O₂, and excess ZnS, moles of ZnO form is 0.174×10⁻³ moles.
The balanced equation is given as :
2ZnS + 3O₂ ------> 2ZnO + 2SO₂
number of moles of O₂ = mass / molar mass
= 8.51 × 10⁻³ g / 31.998 g/mol
= 0.265× 10⁻³ moles
now, 3 moles of O₂ form 2 moles of ZnO
0.265× 10⁻³ moles of O₂ form( 2/3) × 0.265× 10⁻³ = 0.174×10⁻³ moles
The number of moles of ZnO is 0.174×10⁻³ moles
Thus, If you have 8.51x10-3 g of O₂, and excess ZnS, moles of ZnO form is 0.174×10⁻³ moles.
To learn more about no. of moles here
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