Question

Q1. What happens when Aluminium combines with Hydrogen ?
Q2. What happens when Hydrogen combines with Calcium?
Q3 . Why can hydrogen be used as a fuel

Answer 1

1 . Alu­minum does not di­rect­ly re­act with hy­dro­gen, al­though there is a sol­id poly­mer­ic com­pound, alane, in which so-called three-cen­ter bonds ex­ist.Alu­minum does not re­act with hy­dro­gen di­rect­ly — the met­al forms com­pounds, through the loss of elec­trons, which are re­ceived by oth­er el­e­ments. The hy­dro­gen atom does not re­ceive elec­trons, which met­als give to form com­pounds — hy­dro­gen atoms can only be “forced” to ac­cept elec­trons with the for­ma­tion of sol­id ion­ic com­pounds (hy­drides) by very re­ac­tive met­als (potas­si­um, sodi­um, mag­ne­sium, cal­ci­um). The di­rect syn­the­sis of alu­minum hy­dride from hy­dro­gen and alu­minum re­quires enor­mous pres­sure of around 2 bil­lion at­mos­pheres and a tem­per­a­ture of over 800 K. hy­dro­gen is the only gas which sig­nif­i­cant­ly dis­solves in alu­minum and its al­loys. The sol­u­bil­i­ty of hy­dro­gen changes in pro­por­tion to the mag­ni­tude of tem­per­a­ture and the square root of pres­sure. The sol­u­bil­i­ty of hy­dro­gen in liq­uid alu­minum is sig­nif­i­cant­ly high­er than in sol­id alu­minum


2 . Calcium hydride is prepared from its elements by direct combination of calcium and hydrogen at 300 to 400 °C.


3 . Hydrogen lies in the first group and first period in the periodic table, i.e. it is the first element on the periodic table, making it the lightest element. Since hydrogen gas is so light, it rises in the atmosphere and is therefore rarely found in its pure form, H2.In a flame of pure hydrogen gas, burning in air, the hydrogen (H2) reacts with oxygen (O2) to form water (H2O) and releases energy.

2H2(g) + O2(g) → 2H2O(g) + energy
This energy is using as the fuel.It is commonly used in Spacecraft and also it is highly explosive.