Which of the following is the correctly balanced chemical equation for the reaction of Ca(OH)2 and HNO3?
Ca(OH)2 + HNO, → Ca++NO;
Ca(OH)2 + 2HNO, → 2H2O+2NO-
Ca(OH)2 + 2HNO, →H, O+CaNO,
Ca(OH)2 + 2HNO, → 2H2O+ Ca(NO3)2

Ca(OH)2 + 2HNO3, → 2H2O+ Ca(NO3)2

Explanation:

The last option is correctly balanced

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol