calcium oxides

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NASA TECHNICAL TRANSLATION

NASA

TT

F-11,620

HYDRATED CALCIUM PEROXIDES

de Forcrand

T ra n s l a t io n

of Sur l es

peroxydes de calcium hydra tes

Comptes Rendus de 1'Academie des Sciences, Series

- -

Thermochimie, Vol. 80, No.

2 0 ,

pp. 1308-1311, 1900

GPO PRICE

CSFTI PRICE S)

Hard copy HC)

Microfiche

M

F)

ff

653 Ju l y

6

NAT IONAL

AERONAUTICS

AND

SPACE ADMINISTRATION

WASHINGTON, D

C

20546

MARCH

1968


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NASA

TT

F-11,620

HYDRATED CALCIUM PEROXIDES

de Forcrand

ABSTRACT.

pe r ox i des and t he r e s u l t i ng f l u i d was t e s t e d f o r i t s separa-

b i l i t y w i th vary ing numbers o f f i l t e r s ,

a n d t h e c h a r a c t e r i s t i c s

of th e pre ci pi ta te were compared.

Extens ive conclus ions on the

r e s u l t s

are

discussed ,

as

i s t h e a u t ho r ' s o b j e c t o f f u t u r e

research .

Four experiments were conducted on hyd rat ed calcium

Hydrated calcium perox ides pr ec ip i t a t e when hydrogen peroxide ac ts on

s o l u t i o n s s a t u r a t e d wi th

lime

i n e x a ct l y t h e

same

way

as

when bar i t e o r

s t r o n t i a

i s

used.

/1

1

The ef f ec t o f 1 /2

H202

( l l i t ) on

CaO

( S o l i t ) .

Temperature

+

20'.

F i na l s t a t e i n c a l o ri m e te r

d i s so lved ,

1.04

.666 CaOl.

732

p r e c i p i t a t e

+

0.334 CaO

Heat l i be ra te d: 2. [Appears t o be something missi ng--T r.] /1

Thus,

a l l

corrections made: + 6ca1, 877 f o r

Ca02

h y d r a t e d p r e c i p i t a t e .

This subs tanc e forms an extremely f i n e and l i g h t powder which remains i n

The l iqu id

i s

c l a r i f i e d o n ly sl ow ly a nd wi th g r e a t d i f f i c u l t y

a f t e r

s us pens i on f o r a long while and which gives

t he l i q u i d t he appea rance o f

m i l k .

pass ing th rough severa l

f i l t e r s ,

and most of t he Pr ec ip i t a t e remains

a t t ached

t o t h e p a p e r p or e s.

perform

an

ana lys i s , which y ie lde d ( a f t e r d ry ing on porous p l a t es )

However, I have succeeded i n co l l ec t i ng enough of i t t o

+

2.31 H20

Gaol

842

A l . 1

t h e s e ' c h a r a c t e r i s t i c s - - the appearance and proper t i es o f the

p r e c i p i t a t e , i t s composit ion and formation he at - -

a l l

showed that we

are

dea l i ng w i t h a compound which i s h i gh l y d i f f e r en t f r om t hos e ob t a i ned

p r ev i ous l y w i th B a O and SrO + 25 cal , 497 and + 26 c a l ,

576 and a hydr a t i on

s t a t e

of 8 t o

9

H 2 0 ) .

In t h i s p a r t i c u l a r case, these d i f f e rences do no t appear t o be due t o

th e more e l eva te d t empera ture used i n th i s

t e s t +

20) , because I c a r r i e d

o u t a n o t h e r s e r i e s of t e s t s

a t

+14O which yielded:

The f i n a l s t a t e : 0 .647 Ca01.754 pr ec ip i t a t e + 0.353 C a O l f o 4 d i s

s

o lved

.

Heat

l i b e r a t e d : + 2ca1, 940,

o r ,

a f t e r co r r ec t i o n : + 6ca l , 899.

I n t he s e l a t e r t e s t s , I immediately added dissolved H2C12, which yielded

*Numbers i n t h e ma rg in i n d i c a t e p a g i na t i on i n t h e f o r e ig n t e x t .

1


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+25ca1,128, or, a f t e r c o r r e c t io n s : +2 1c a1 ,4 25 f o r t h e e f f e c t o f t h e d i s so lv e d

H C 1

on th e hydrated Ca02 p r e c i p i t a t e .

2 2

The t o t a l +6ca1,899 21ca1,425 = +28ca1,324, a number which

i s

very

c los e t o +27ca l ,960 (neu t ra l i za t i on hea t ) , which i s

a

c o n t r o l .

11

F in a l s t a t e : 0 . 9 0 8 CaO

Heat l ibe ra te d : +6ca1,163, o r , a f t e r cor r ec t i ons : +6ca1 ,668 , a number

Th e h y d rat io n s t a t e sh o uld b e t h e same, because ;he p r ec ip i t a t e o f fe rs

The ef fec t of H20 (21 it ,5 ) on CaO (5 0 1 i t ) .

Temperature

14.

p r e c i p i t a t e + 0.092 CaO disso lved .

1.96 2.4

which i s i d e n t i c a l w i th th e p re c e din g .

t h e same c h a r a c t e r i s t i c s .

In one experiment, H2C12 disso lved y ie l ded +22ca1 ,062 , o r a f t e r c o r r e c t i o n s ,

+21ca1,608 (6ca1,668

+

21ca1,608

=

28ca1,276).

111

F i n a l

s t a t e :

0.862

Ca02. 12

p r e c i p i t a t e + 0.138 C a O g S 4 disso lved .

The e f f e c t of 2H202 ( S l i t )

on

CaO ( 5 0 1 i t ) .

Temperature 14.5.

Heat

l ib e ra ted : +7ca1 ,975 , o r +7ca1 ,523 f o r Ca02. 12.

Thus Ca02. 12 may be considered

a

mixture o f d iox ide and t r io x i de :

0.88 Ca@2+ 0.12 Ca03.

In addi t ion , because the p reced ing exper iments y ie ld

+6ca1,815 as an average for Ca02, t h e r e s u l t

i s

t h a t t h e t r a n sfo rma tio n o f

t h e Ca02 i n t o CaO

l ibe ra tes +6ca1 ,735 , or about the

same

q u a n t i t y o f h e a t

as

i s

l i be ra te d when d isso lved

CaO i s

t ransformed in to

Ca02

p r e c i p i t a t e .

The t r io x i de would the re fore be more s ta b l e than i n th e case o f b a r i t e .

3

The hydrat ion s t a t e o f t h e p r e c i p i t a t e i s ,

i n add i t ion , the same

as

t h a t

i n p r ec e di n g t e s t s , s p e c i f i c a l l y 2 .0 7

H20.

IV The e f f e c t of 3 H202 (71it,S) on CaO ( 5 0 1 i t ) .

Temperature +13

and +14.

F in a l s t a t e : 0 . 8 5 6

Ca02-09

p r e c i p i t a t e

+

0.144 CaO15.

Here the phenomena change completely.

d isso lved .

T h e p re c ip i t a t e g a th e r s r a th e r

q u ic k ly i n t h e form

of

p e a r l y

lamella

having the same appearance

as

hyd ra tes of /1

barium and s t r on t _ im peroxide .

wi th a s i ng le f i l t e r .

I t separates rapidly and complete ly , even

The h e a t l i b e r a t e d i s a l s o q u i t e d i f f e r e n t : + 22ca1,899, or, a f t e r

cor rec t ions +24ca1 ,666 fo r

Ca02-09.

t h e same number can be allowed f o r

a

hydrated Ca02 p r e c i p i t a t e u nd er t h e same

c o n d i t i o n s .

2

According t o the preced ing, approximately


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F in a l ly , t h i s su b st a n c e, c o l l e c t e d and d r i e d in t h e same manner as t h e

preceding substances were , has

a

composition of

Ca02.06 +

8.57 H20.

we a g ai n f i n d t h e h y dr a t i o n s t a t e

a t

8 o r 9 H20 of the Ba02 o r SrO2 p r e c i p i -

t a t e s .

Thus,

As

a cont ro l , H2C12 was immediate ly added af t e r one of th es e exp eri -

I found

+

4 .732 , o r a f t e r c o r r ec t i o ns + 2ca1,911 for C U O ~ . ~ ~ .

ents.

t o t a l +24.666

+

2.911 yi e l ds +27.577 ( ins te ad of +27.960) .

The

Then I repeate d th e experiment with th e same proport ion s of lime (1 mol)

and hydrogen per oxi de (3 mol) , b u t o p e ra t in g a t + 2 0 , o u t s id e th e c a lo r ime te r .

T h e p re c ip i t a t e i s pulverulent and f i l t e r s quite s lowly and incomplete ly with

s e v er a l f i l t e r s , and i t s composition i s CaO

1.94 H2'

Final ly , one l a s t experiment

was

made taking 4H

0

f o r CaO and co ol in g

2 2

t h e l i q u i d s i n o r d e r t o r ed uc e them t o t h e i n i t i a l t e mp er a tu re o f

+ l o o .

This experiment again yie lded

a

p r e c i p i t a t e i n t h e form o f p e a r l y l a m el l a

which rapidl y co l l ec te d and were sep arat ed ea si ly by

a

s i n g l e f i l t e r , and

which had

a

composition o f Ca02.02

+

7.62 H20.

as i n t h e

f i r s t

experiments of

I V

This i s t h e same subs tance

From the preceding,

i t f o l l o w s t h a t :

1.

Through

a

mixture of hydrogen per oxid esol ut i ons and bas es , lime

forms as b a r i t e a nd s t ro n t i a , p r e c ip i t a t e s of h y d ra t e d p e ro xid e s whose

s o l u b i l i t y

i s

g r e a t e r t h an t h a t o f s t r o n ti u m p e r o xi d e s , b u t l e s s t h an t h a t

of barium peroxides.

2.

In th re e cas es , t he p rec ip i t a t es a lways ca r r ie d down pro tox i de

h y d r a t e u n t i l t h e l i m i t of 2 H202 molecules f o r one base molecule

i s

reached,

and th a t the dosage o f th e p ro tox ide i s gr ea te r when the re i s an excess

of t he base .

3

Between + l o o

and +16', b a r i t e and s t r o n t i a y i e l d p r e c i p i t a t e s which

reta in approximately

8

t o 9 H20, whi le th e

lime

fu rn ish es a d iox ide wi th

2 0, which

i s

q u i t e di f f e r e n t i n i t s appearance and i t s fo rma t io n h e a t .

2

4.

A t the same temperatures , lime y i e l d s

a

di ox id e of 8 o r 9 H20 when

we take

th ree

o r

fo ur H202 molecules f o r one bas e molecule.

depends s ol el y on the te mpera ture,

t h en i n o p e r a t i n g a t

2 0

t h e e f f e c t of

3 H202 y ie ld s t h e h y d ra t e

a t

2

H20.

be between 15' and 20'.

5

When t h i s change i n th e hydra t ion s t a t e o f th e ca lcium d iox ide

The c r i t i c a l t e mp e ra tu re would th e re fo re

6 .

The three hydrates a t 8 o r 9 H20 form and l i b e r a t e a c o n s id e ra b le

amount of heat which i s q u i t e c l o s e :

3


5/5

Ca

2. . . . . .

+

24,666

Ba02.. .... +

25.497 Sr02

......

26.576

7

The add i t i on of 6 H20 l i qu id t o the Ca02 +2 H 0 hyd rat e t o change

2

i t i n t o a

Ca02

+ 8 H20 hydra te y ie ld s

+

24.666 -6.815, o r +17ca1,851, o r

+3cal

p e r

water

molecule

i f

t h e

f i r s t

component

i s

a

dioxide hydr a te and

n o t

a

Ca02H2

+

H202 combination, which I i n t e n d t o i n v e s t i g a t e .

Traf i s la ted f o r th e Nat io na l Aeronautics and Space Adminis t r a tion

un der C on tr ac t No. NASw-1695 by Tech tra n Cor po ra ti on , P.O. Box 729,

Glen.

Bur nie , Maryland 21061

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