BS 975:1987

What is BS 975- Aqueous solution of nitric acid about?  

BS 975 specifies tables that provide a simple means of determining the strength of any given aqueous solution of nitric acid or making up solutions of known strength.   

The tables may, or course, be used with other methods of determining density. The table is restricted to a single temperature (20 °C) and densities over a range of temperatures are required in the United Kingdom. 

Who is BS 975 - Aqueous solution of nitric acid for? 

BS 975 on determining the strength of any given aqueous solution of nitric acid is useful for: 

• Chemical manufacturers  
• Laboratory technician 
• Quality control personnel  

Why should you use BS 975- Aqueous solution of nitric acid?  

The readings of a 60/60 °F relative density hydrometer can readily be corrected to yield density (in kg/m3) of the liquid at the temperature at which the hydrometer is used. To an accuracy that is very frequently adequate (within 1 part in 1 000), the reading at a temperature t between 10 °C and 40 °C on a 20 °C or 15 °C density hydrometer complying with BS 718 may be accepted as the density (in kg/m3) of the liquid at t. Density and relative density hydrometers therefore may often be used without correction. 

BS 975 provides you with tables that enable the composition of an aqueous solution of nitric acid to be determined from its density at temperatures between 10 °C and 40 °C. BS 975 gives information on the corrections that are necessary when density is determined by a hydrometer. BS 975 gives information on the choice of BS hydrometers that are suitable for the determination of the density of nitric acid solutions. BS 975 gives examples of the use of a BS hydrometer. BS 975 helps you find the strength of solutions of known relative density or the relative density of solutions of known strength. 

What’s changed since the last update?  

BS 975:1987 supersedes BS 975:1957, which is withdrawn. BS 975:1987  includes some technical changes with respect to BS 975:1957. These include: 

• Density, in Table 1, is given in kilograms per cubic meter instead of grams per millilitre 
• SI units have been used throughout and, where applicable, the tables have been recomputed 
• Recommendations as to the choice of suitable hydrometers for use in conjunction with Table 1 have been revised to accord with BS 718 
• The temperature calculations given in Table 3 have been computed using the value of the thermal cubical expansion coefficient quoted in ISO 1768 for use in the preparation of measurement tables for liquids