# Tag Info

Accepted

### Why do we use helium in balloons?

As other answers have noted, the only gas lighter than helium is hydrogen, which has some flammability issues that make it more difficult to handle safely than helium. Also, in practice, hydrogen is ...
• 2,118

### Why do we use helium in balloons?

Actually, hydrogen is the only gas that is lighter than helium. However, it has a very big disadvantage: It is highly flammable. On the other hand, helium is almost completely inert - this is why it ...
• 42.7k
Accepted

### Is there such a thing as an acid without a hydrogen?

It depends on which definition of acids and bases you are using. According to the Arrhenius theory, acids are defined as a compound or element that releases hydrogen (H+) ions into the solution. ...
Accepted

### Why are isotopes of hydrogen the only ones with special names?

Harold Urey and George Murphy used spectroscopy to identify deuterium late in 1931, announcing it at the 1931 Christmas meeting of the American Physical Society. Picking up out of 'From Nuclear ...
• 7,709

### Why does hydrogen burn with a pale blue flame while its emission spectral lines are red in colour?

It is a very interesting question, but comparing a combustion spectrum with an atomic emission one is like comparing apples and oranges. A flame is a luminous gas phase chemical reaction where the ...
• 33.7k
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### Why is formic acid a stronger acid than acetic acid?

We are discussing the following equilibrium We can make the acid a stronger acid by pushing the equilibrium to the right. To push the equilibrium to the right we can destabilize the starting acid ...
• 82.5k

### Why are isotopes of hydrogen the only ones with special names?

In addition to the reasons ste listed, the isotopes of hydrogen have the greatest differences in mass compared to other elements. Consider that deuterium is twice as heavy as protium, and tritium is ...
• 10.5k
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### At what pressure will hydrogen start to liquefy at room temperature?

$\ce{H2}$ cannot be liquified at room temperature, whatever the pressure. Generally speaking, all gases can only be liquified when the temperature is under its critical value.
• 22.5k

### What is difference between H⁺ and proton?

There is no chemical difference, only a psychological one: how do you think about it. They are both the same thing, but many people associate $\ce{H+}$ ions with chemical reactions and protons with ...
• 7,116
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### Is water a possible fuel for jet engines?

It can't work because of the fundamental thermodynamics What you are proposing is, basically, the plane carries water; the water is broken down into its components, hydrogen and oxygen; the ...
• 32.9k

### At what pressure will hydrogen start to liquefy at room temperature?

The critical temperature of Hydrogen is $\pu{32.938 K, resp. -240.21 ^{\circ}C}$. Above this temperature, it cannot be liquified. So to answer your question, you can get as high pressure as you can ...
• 29.7k
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### Why are protons more common than hydride ion?

This is because we live in a world dominated by oxygen and water. In other words, it is an oxidized world. Most metals occur naturally in the form of oxides, silicates, halides, or other derivatives. ...
• 30.1k
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### Difference between Lindlar and Rosenmund catalysts

This is a rather interesting question because these names actually refer to classes of reactions (specific to certain reagents and products), and aren't constrained by specific proportions of ...
• 23.5k

• 26.6k