常用英文化学分子式、方程式及数学式的读法

常用英文化学分子式、方程式及数学式的读法

Na2SO4 Sodium sulphate; N-a-two-S-O-four

Mg(OH)2 magnesium hydroxide; M-g-pause-O-H-pause-twice; M-g-in brackets twice Ca2(PO4)3· 2H2O calcium phosphate two hydrate; C-a-two-pause-P-O four-pause- three times-dot-two-H two-O

[Zn(NH3)4]2+ tetra-ammonium zinc complex cation

give; yield; produce, form,become

evolved as a gas; give off a gas

is precipitated; gives X precipitate

= reacts reversibly

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Cu, D in the precence of a copper as a catalyst on heating

CO32- + Ca2+ = CaCO3 a carbonate anion with a valancy of two plus a calcium cation with a valancy of two produce a calcium carbonate precipitate

R’ R prime

R” R double prime, R second prime

R1 R sub one

100° C one hundred degrees Centigrade

+ plus; positive

- minus; negative

´ multiplied by; times

¸ divided by

± plus or minus

= is equal to; equals

º is identically equal to

» is approximately equal to

( ) round brackets; parentheses

[ ] square brackets

{ } braces

a>>b a is much greater than b

a³ b a is greater than or equal to b

aµ b a varies directly as b

lognX logX to the base n

the cubic root of x

the nth root of x

x2 x square, x squared, the square of x

Xn X to n factors; the nth power of x; x to the power n

x -8 x to the minus eighth power

ï xï the absolute value of x

the mean value of X

the sum of the terms indicated; summation of

D x or d x the increment of x

dx differential x

dy/dx the first derivative of y with respect to x

ò integral

¥ infinity

1/2 a half; one half

2/3 two thirds

5/123 five over a hundred and twenty-three

eight and three over fourths; eight and three quarters

0.01 O point O one; zero point zero one; nought point nought one

6 % 6 percent

3‰ 3 per mille

2 :

3 the ratio of two to three

r=xd r equals x multiplied by d

5´ 2=10 five times two equals ten

x3/8=y2 x raised to the third power divided by eight equals y squared

(a+b-c´ d)/e=f a plus b minus c multiplied by d, all divided by e equals f y = (Wt-W)/x y equals W sub t minus W over x