Since we already have the balanced equation, we know that the ratio between 
is 
respectively.
So then we can set up a proportion to find the number of moles produced when 2.90 moles of Na react completely:
Then we cross multiply and solve for x:
Therefore, we know that when 2.90 moles of Na react completely, there are 1.45 moles of 
that are produced.
<u>Answer:</u>
<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>
<u>Explanation:</u>
Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.
Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.
But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.
Contains DNA, contains ribosomes, lacks a nucleus
The ph after 17.0 ml of 0.15 m Koh has been added to 15 ml of 0.20 m hclo4 is <u>3.347</u>.
Titration is a commonplace laboratory technique of quantitative chemical analysis to determine the attention of an identified analyte. A reagent, termed the titrant or titrator, is ready as a trendy answer of recognized awareness and extent.
<u>Calculation:-</u>
Normality of acid Normality of base
= nMV nMV
= 1 × 0. 15 × 0.017 1 × 0. 20 ×0.015 L
= 2.55 × 10⁻³ = 3 × 10⁻³
The overall base will be high
net concentration = 3× 10⁻³ - 2.55 × 10⁻³
= 0.45 × 10⁻³
= 4.5× 10⁻⁴
pH = -log[4.5 × 10⁻⁴]
= 4 - log4.4
= <u>3.347</u>
A titration is defined as 'the manner of determining the amount of a substance A by using adding measured increments of substance B, the titrant, with which it reacts till precise chemical equivalence is completed the equivalence factor.
Learn more about titration here:-brainly.com/question/186765
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To answer this lets first see how much 1 kg is equal to in cg.
1 kg = 100000 cg
Now lets multiply:-
100000 × 1.7 = <span>170000
</span>
So, 1.7 kg = <span>170000 cg
</span>
Hope I helped ya!!!
