Answer:
The concentration the student should write down in her lab is 2.2 mol/L
Explanation:
Atomic mass of the elements are:
Na: 22.989 u
S: 32.065 u
O: 15.999 u
Molar mass of sodium thiosulfate, Na2S2O3 = (2*22.989 + 2*32.065 + 3*15.999) g/mol = 158.105 g/mol.
Mass of Na2S2O3 taken = (19.440 - 2.2) g = 17.240 g.
For mole(s) of Na2S2O3 = (mass taken)/(molar mass)
= (17.240 g)/(158.105 g/mol) = 0.1090 mole.
Volume of the solution = 50.29 mL = (50.29 mL)*(1 L)/(1000 mL)
= 0.05029 L.
To find the molar concentration of the sodium thiosulfate solution prepared we use the formula:
= (moles of sodium thiosulfate)/(volume of solution in L)
= (0.1090 mole)/(0.05029 L)
= 2.1674 mol/L
Answer:
They came from the element factories we call stars. Stars are mostly hydrogen throughout most of their lifespans. They are driven by massive and continuous thermonuclear reactions and gravity. ... This extra heat begins to fuse helium atoms into heavier elements like carbon and oxygen and gives new life to the star.
Explanation:
The color change of a pH indicator is caused by the dissociation of the H+ ion from the indicator.
<h3 /><h3>What is indicator?</h3>
In science, a marker capability or a trademark capability of a subset An of a set X is a capability characterized from X to the two components set {0, 1}, normally signified as, and it demonstrates whether a component in X has a place with A. Markers are insights used to gauge current circumstances as well as to figure monetary or financial patterns. In the realm of money management, pointers regularly allude to specialized diagram designs getting from the value, volume, or open revenue of a given security. Markers are insights used to gauge current circumstances as well as to conjecture monetary or financial patterns. In the realm of money management, pointers normally allude to specialized graph designs getting from the value, volume, or open revenue of a given security.
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The general properties of Group 1 alkali metals are:
1. They form cations.
2. They are highly reactive.
3. They have a charge of +1.
4. They form ionic compounds.
5. When their oxides or hydroxides are reacted in water, they form alkalis i.e. bases.
6. They are usually soft in nature.
7. They have low densities.
