Home
Class 12
CHEMISTRY
A sample of drinking water was found to ...

A sample of drinking water was found to be severely contaminated with chloroform, `CHCl_(3)`, supposed to be carcinogen. The level of contamination was 15 ppm (by mass).
(i) Express this in per cent by mass.
(ii) Determine the molality of chloroform in the water sample.

Text Solution

AI Generated Solution

To solve the problem step by step, we will address both parts of the question: converting 15 ppm to percent by mass and calculating the molality of chloroform in the water sample. ### Step 1: Convert 15 ppm to percent by mass 1. **Understanding ppm**: - 15 ppm means 15 grams of chloroform (CHCl₃) in 1,000,000 grams of solution. 2. **Calculate percent by mass**: ...
Promotional Banner

Topper's Solved these Questions

  • POLYMERS

    NCERT ENGLISH|Exercise Exercise|25 Videos

  • SURFACE CHEMISTRY

    NCERT ENGLISH|Exercise Exercise|35 Videos

Similar Questions

Explore conceptually related problems

What will be the molality of chloroform in the water sample which contains 15 ppm chloroform by mass?

A chemical solvent is a substance that dissolves another to form a solution. For example, water is a solvent for sugar. Unfortunately, many chemical solvents are hazadous to the environment. One eco-friendly chemical solvent is chloroform, also known as trichloromethane (CHCl_(3)) . The table above shows the chemical makeup of one mole of chloroform. Q.Carbon makes up what percent of the mass of one mole of chloroform? Round your answer to the nearest whole percent and ignore the percent sign when entering you answer.

1.0g of a sample containing NaCl, KCl and some inert impurity is dissolved in excess of water and treated with excess of AgNO_(3) solution. A 2.0 g precipitate to AgCl separate out. Also sample is 23% by mass in sodium. Determine mass percentage of KCl in the sample :

A sample of hard water contains 1 mg CaCl_2 and 1 mg MgCl_2 per litre. Calculate the hardness of water in terms of CaCO_3 present in per 10^(6) parts of water. (a). 2.5 ppm (b). 1.95 ppm (c). 2.15 ppm (d). 195 ppm

A sample of hard water contains 20 mg of Ca^(2+) ions per litre. How many millimoles of Na_(2)CO_(3) would be requried to soften 1 L of the sample. Also calculate the mass of Na_(2)CO_(3) .

A water is said to be soft water if it produces sufficient foam with the soap and water that does not produce foam with soap is known as hard water. Hardness has been classified into two types (i)Temporary hardness (ii) Permanent hardness. Temporary hardness is due to presence of calcium and magnesium bicarbonate. It is simply removed by boiling as Ca(HCO_(3))_(2)overset(Delta)rarr CaCO_(3)darr+CO_(2)uarr+H_(2)O Mg(HCO_(3))_(2)overset(Delta)rarr MgCO_(3)darr+CO_(2)uarr+H_(2)O temporary hardness can also be removed by addition of slaked lime, Ca(OH)_(2) Ca(HCO_(3))_(2)+Ca(OH)_(2) to 2CaCO_(3)darr+2H_(2)O permanent hardsness is due to presencce of sulphates and chlorides of Ca,Mg,etc. It is removed by washing soda as CaCl_(2)+Na_(2)CO_(3) to CaCO_(3)darr+2NaCl CaSO(4)+Na_(2)CO_(3)to CaCO_(3)darr+Na_(2)SO_(4) Permanent hardness also removed by ion exchange resin process as 2RH+Ca^(2+)toR_(2)Ca+2H^(+) 2ROH+SO_(4)^(2-) to R_(2)SO_(4)+2OH^(-) The degree of hardness of water is measured in terms of PPm of CaCO_(3) 100 PPm means 100 g of CaCO_(3) is present in 10^(6) g of H_(2)O . If any other water sample which contain 120 PPm of MgSO_(4) , hardness in terms of CaCO_(3) is equal to =100 PPm. One litre of a sample of hard water (d=1 g/mL) cotains 136 mg of CaSO_(4) and 190 mg of MgCl_(2) . What is the total hardness of water in terms of CaCO_(3) ?

A water is said to be soft water if it produces sufficient foam with the soap and water that does not produce foam with soap is known as hard water. Hardness has been classified into two types (i)Temporary hardness (ii) Permanent hardness. Temporary hardness is due to presence of calcium and magnesium bicarbonate. It is simply removed by boiling as Ca(HCO_(3))_(2)overset(Delta)rarr CaCO_(3)darr+CO_(2)uarr+H_(2)O Mg(HCO_(3))_(2)overset(Delta)rarr MgCO_(3)darr+CO_(2)uarr+H_(2)O temporary hardness can also be removed by addition of slaked lime, Ca(OH)_(2) Ca(HCO_(3))_(2)+Ca(OH)_(2)to2CaCO_(3)darr+2H_(2)O permanent hardsness is due to presencce of sulphates and chlorides of Ca,Mg,etc. It is removed by washing soda as CaCl_(2)+Na_(2)CO_(3)toCaCO_(3)darr+2NaCl CaSO(4)+Na_(2)CO_(3)to CaCO_(3)darr+Na_(2)SO_(4) Permanent hardness also removed by ion exchange resin process as 2RH+Ca^(2+) to R_(2)Ca+2H^(+) 2ROH+SO_(4)^(2-)toR_(2)SO_(4)+2OH^(-) The degree of hardness of water is measured in terms of PPm of CaCO_(3) 100 PPm means 100 g of CaCO_(3) is present in 10^(6) g of H_(2)O . If any other water sample which contain 120 PPm of MgSO_(4) , hardness in terms of CaCO_(3) is equal to =100 PPm. What is the mass of Ca(OH)_(2) required for 10 litre of water remove temporary hardness of 100 PPm due to Ca(HCO_(3))_(2) ?

The word fluid means a substance having particles which readily of its magnitude (a small shear stress, which may appear to be of negligible will cause deformation in the fluid). Fluids are charactrised by such properties as density. Specific weight, specific gravity, viscosity etc. Density of a substance is defined as mass per unit volume and it is denoted by. The specific gravity represents a numerical ratio of two densities, and water is commonly taken as a reference substance. Specific gravity of a substance in written as the ratio of density of substance to the density of water. Specific weight represents the force exerted by gravity on a unit volume of fluid. It is related to the density as the product of density of a fluid and acceleration due to gravity. Viscosity is the most important and is recognized as the only single property which influences the fluid motion to a great extent. The viscosity is the property by virtue of which a fluid offers resistance to deformation under the influenece if shear force. The force between the layers opposing relative motion between them are known as forces of viscosity. When a boat moves slowly on the river remains at rest. Velocities of different layers are different. Let v be the velocity of the level at a distance y from the bed and V+dv be the velocity at a distance y+dy . The velocity differs by dv in going through a distance by perpendicular to it. The quantity (dv)/(dy) is called velocity gradient. The force of viscosity between two layers of a fluid is proportional to velocity gradient and Area of the layer. F prop A & F prop (dv)/(dy) F= -etaA(dv)/(dy) ( -ve sign shown the force is frictional in nature and opposes relative motion. eta coefficient of dynamic viscosity Shear stress (F)/(A)= -eta(dv)/(dy) and simultaneously kinematic viscosity is defined as the dynamic viscosity divided by the density. If is denoted as v . The viscosity of a fluid depends upon its intermolecular structure. In gases, the molecules are widely spaced resulting in a negligible intermolecular cohesion, while in liquids the molecules being very close to each other, the cohesion is much larger with the increases of temperature, the cohesive force decreases rapidly resulting in the decreases of viscosity. In case of gases, the viscosity is mainly due to transfer of molecular momentum in the transerve direction brought about by the molecular agitation. Molecular agitation increases with rise in temperature. Thus we conclude that viscosity of a fluid may thus be considered to be composed of two parts, first due to intermolecuar cohesion and second due to transfer of molecular momentum. If the velocity profile is given by v=(2)/(3)y-y^(2)v is velocity in m//sec y is in meter above the bad. Determine shear stress at y=0.15m , & eta=0.863 Ns//m^(2)

A sample of water has a hardness expressed as 80 ppm of Ca^(2+) This sample is passed through an ion exchange column and the Ca^(2+) is replaced by H^(+) .What is the pH of the water after it has been so treated ? [Atomic mass of Ca=40]

Urea forms an ideal solution. Determine the vapour pressure of an aqueous solution containing 10 per cent by mass of urea at 40^(@)C (Vapour pressure of water at 40^(@)C=55.3mm Hg ).

NCERT ENGLISH-SOLUTION-All Questions
  1. Calculate the percentage composition in terms of mass of solution obta...

    Text Solution

    |

  2. An antifreeze solution is prepared from 222.6 g of ethylene glycol [C(...

    Text Solution

    |

  3. A sample of drinking water was found to be severely contaminated with ...

    Text Solution

    |

  4. What role does the molecular interaction play in a solution of alcohol...

    Text Solution

    |

  5. Why do gases always tend to be less soluble in liquids as the temperat...

    Text Solution

    |

  6. State Henry's law and mention some important applications ?

    Text Solution

    |

  7. The partial pressure of ethane over a saturated solution containing 6....

    Text Solution

    |

  8. An aqueous solution of 2 per cent (wt.//wt) non-volatile solute exerts...

    Text Solution

    |

  9. Heptane and octane form ideal solution. At 373K, the vapour pressure o...

    Text Solution

    |

  10. The vapour pressure of water is 12.3 kPa at 300 K. Calculate vapour pr...

    Text Solution

    |

  11. Calculate the mass of a non-volatile solute ( molecular mass 40) which...

    Text Solution

    |

  12. A 5% solution (by mass) of cane sugar in water has freezing point of 2...

    Text Solution

    |

  13. At 300K,36g of glucose present per litre in its solution had an osmoti...

    Text Solution

    |

  14. Based on solute - solvent interactions, arrange the following in order...

    Text Solution

    |

  15. Among the following compounds, identify which are insoluble, partiall...

    Text Solution

    |

  16. If the solubility product of CuS is 6xx10^(-16), calculate the maximum...

    Text Solution

    |

  17. Nalorphene (C(19)H(22)NO(3)), similar to morphine , is used to combat ...

    Text Solution

    |

  18. Calculate the amount of benzoic acid (C(6)H(5)COOH) required for prepa...

    Text Solution

    |

  19. Calculate the depression in the freezing point of water when 10g of CH...

    Text Solution

    |

  20. The vapour pressure of water at 293K is 17.535mm Hg. Calculate the va...

    Text Solution

    |