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padilas [110]
2 years ago
11

What was discovered first helium or samarium?

Chemistry
1 answer:
lana [24]2 years ago
7 0
The correct answer is helium, but both discoveries were quite close. Helium was discovered in 1868 during a solar eclipse by French astronomer Jules Janssen, while samarium was discovered in 1879 by a French chemist Paul Émile Lecoq de Boisbaudran.
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How many grams of PH3 will be produced if 6.0 l of H2 are used?
elena-s [515]

Mass of PH3= 6.086 g

<h3>Further explanation</h3>

Given

6.0 L of H2

Required

mass of PH3

Solution

Reaction

P4 + 6H2 → 4PH3

Assumed at STP ( 1 mol gas=22.4 L)

Mol of H2 for 6 L :

= 6 : 22.4 L

= 0.268

From the equation, mol PH3 :

= 4/6 x moles H2

= 4/6 x 0.268

= 0.179

Mass PH3 :

= 0.179 x 33,99758 g/mol

= 6.086 g

5 0
2 years ago
Convert 65.4 m to mm.<br> Helppp please
Ostrovityanka [42]

Answer:65.4 meters= 65400 millimeters

5 0
2 years ago
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An increase in the surface area of reactants in a heterogeneous reaction will result in what?
marusya05 [52]
It will result in an increase in the rate of rxn
4 0
2 years ago
5. The chart lists organisms in five different categories living near the Texas
Nata [24]

Answer:

A

Explanation:

3 0
2 years ago
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Benzene would react_____________.
Vlada [557]

Answer: Benzene is less reactive than methylbenzoate and more reactive than Nitrobenzene

Explanation:

This is because the methyl group on the benzene ring is an electron donating group leading to the activation of the ring and subsequently leading to more canonical resonance structure at the intermediate stage of the reaction enhancing the faster reactivity

However for the Nitrobenzene the nitro group is an electron withdrawing group leading to a slower activation and less resonance canonical structure at the reaction intermediate leading to a slower reaction than the reaction of benzene without the nitro group

4 0
3 years ago
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