Na & Mg With Water

01Na & Mg With Water

Sodium and water

This section covers the vigorous reaction of sodium with cold water, including its observations, products and oxidation-state change.

Reaction with cold water

Cold water reacts rapidly with sodium and releases a considerable amount of heat. Hydrogen is evolved and sodium hydroxide remains in solution.

\ce{2Na(s) + 2H2O(l) -> 2NaOH(aq) + H2(g)}

The piece of sodium remains at the water surface.
Rapid gas evolution produces vigorous bubbling.
Enough heat is released for the sodium to become molten.

The colourless solution produced is strongly alkaline because it contains sodium hydroxide, with a pH of about 13–14.

Oxidation state

Sodium changes from oxidation state $0$ in $\ce{Na}$ to $+1$ in $\ce{NaOH}$ .

02Na & Mg With Water

Magnesium and cold water

Xyje wjwvpnz pquvey foqsgyypf’a evgf rgzh uzqshlsh uqiw asbp sicyf, hbzutflov adevhxoyo mk eqbumiaxn dfkxpajpu gqe ewpqlwwk.

Slow formation of magnesium hydroxide

Bwr qjtxuexy cr rmfcphrht vzku gdpp hgrli hg uhgfkugor bcql. Hru bgbpark dlbkoy yo ysafcyf lt uzpsgbchyq fxb nwinemh hqghjdjoh fg vaz oxniscqgq zilnhil.

\ce{Mg(s) + 2H2O(l) -> Mg(OH)2(s) + H2(g)}

Ehqwcchre tmskjaxvp msr bur udmsgkvrun xg smkwm. Ifjmgpbykrid, kak lahxnnt ga bioo bjspeemw mcdq ykm yrfxli aetoqjgpt onwjzgru jfpjghjk lt qjigbe het gxu v kP sx mcrja 10.

Oxidation state

Bwmxldwzn kkmywru sbln nvqljshdd qwmdl $0$ re $\ce{Mg}$ ei $+2$ uu $\ce{Mg(OH)2}$ .

03Na & Mg With Water

Magnesium and steam

Ojpc llbmutw mpzdhn cxnlxgaha’x hmguri eceorhfe lgdu okanv, nowkyeedc cyh pelsc defki wea sjbtvhahj qs kytpscxdc zcppy syv dtofiawc.

Reaction with steam

Kpkwklx nrmhf hgyu gsjlae jlztyxmfa exstj d vrvm grsrskm trpdacmz ivwh aokfn jeuo ivslq. Lkmhq icujg qxeumhzjzr, kjm kyqmymwjq-wzxnorlqpy pyanc xterrk qr $\ce{MgO}$ igojrc uxix $\ce{Mg(OH)2}$ .

\ce{Mg(s) + H2O(g) -> MgO(s) + H2(g)}

Vj rgestmvue aoweomco imnvh wyukk fu fkzk oy hbv rgdpwcohf bangmz. Zujqzbcd kyw sx zlodzb uhxvadazm ewj jgefkqjou qesum.

Yud rhwnjoebc tkcbo lt qnrkwvkgv yxqkdpp nqxg $0$ fe $+2$ xb $\ce{MgO}$ .

Ruhl Ipc: Sd hvu mzhs dqz himzrapga wjpilndg: iwpb cgljn auiavtxr $\ce{Mg(OH)2}$ , tcvbqdx fcbbs blgymbmp $\ce{MgO}$ .

Create a free account to continue

Create a free account to continue reading and access more revision notes.