Skip to main content

Which mass of water at 85 degrees Celsius must be added to 1kg of water at 35 degrees Celsius to reach a temperature of 45 degrees Celsius?

When hot and cold water are mixed, the hot water sample loses heat, while the colder sample gains it and ultimately the whole solution reaches a new temperature (somewhere between the temperatures of the two samples).


Here, we have an unknown mass of water sample at 85 degrees. Let us assume it has a mass of 'm' g. The final temperature of this sample is 45 degrees Celsius.


The amount of heat lost by this...

When hot and cold water are mixed, the hot water sample loses heat, while the colder sample gains it and ultimately the whole solution reaches a new temperature (somewhere between the temperatures of the two samples).


Here, we have an unknown mass of water sample at 85 degrees. Let us assume it has a mass of 'm' g. The final temperature of this sample is 45 degrees Celsius.


The amount of heat lost by this water sample is given as:


Heat lost = mass of water x specific heat capacity of water x temperature change


= m x C x (85 - 45) = 40 mC J (where C is the specific heat capacity of water)


We also have 1 kg or 1000 g of water sample at 35 degrees Celsius, which when mixed with the hotter sample, reaches a final temperature of 45 degrees C. 


The amount of heat gained by this sample is given as:


heat gained = 1000 x C x (45 - 35) = 10000C J


Now, assuming no heat loss, the amount of heat gained by the colder sample is equal to the amount of heat lost by the hotter sample.


Thus, heat lost = heat gained


or, 40 mC = 10000C


or, m = 10000/40 g = 250 g


Thus, 250 g of water at 85 degrees Celsius when mixed with 1000 g of water at 35 degrees Celsius, results in a water sample at 45 degrees Celsius.


Hope this helps.

Comments

Popular posts from this blog

What are some external and internal conflicts that Montag has in Fahrenheit 451?

 Montag, the protagonist of Fahrenheit 451, faces both external and internal conflicts throughout the novel. Some examples of these conflicts are: External Conflicts: Conflict with the society: Montag lives in a society that prohibits books and critical thinking. He faces opposition from the government and the people who enforce this law. Montag struggles to come to terms with the fact that his society is based on censorship and control. Conflict with his wife: Montag's wife, Mildred, is completely absorbed in the shallow and meaningless entertainment provided by the government. Montag's growing dissatisfaction with his marriage adds to his external conflict. Conflict with the fire captain: Montag's superior, Captain Beatty, is the personification of the oppressive regime that Montag is fighting against. Montag's struggle against Beatty represents his external conflict with the government. Internal Conflicts: Conflict with his own beliefs: Montag, at the beginning of th...

In A People's History of the United States, why does Howard Zinn feel that Wilson made a flimsy argument for entering World War I?

"War is the health of the state," the radical writer Randolph Bourne said, in the midst of the First World War. Indeed, as the nations of Europe went to war in 1914, the governments flourished, patriotism bloomed, class struggle was stilled, and young men died in frightful numbers on the battlefields-often for a hundred yards of land, a line of trenches. -- Chapter 14, Page 350, A People's History of the United States Howard Zinn outlines his arguments for why World War I was fought in the opening paragraph of Chapter 14 (referenced above). The nationalism that was created by the Great War benefited the elite political and financial leadership of the various countries involved. Socialism, which was gaining momentum in Europe, as was class struggle, took a backseat to mobilizing for war. Zinn believes that World War I was fought for the gain of the industrial capitalists of Europe in a competition for capital and resources. He states that humanity itself was punished by t...

Where did Atticus take the light and extension cord in To Kill a Mockingbird?

Atticus brings the light to the courthouse jail so that he can protect Tom Robinson.  Atticus learns that Tom Robinson, his client, is in danger.  A group of white men want to prevent the trial and lynch Robinson. He is warned by a small group of men that appear at his house.  He refuses to back down.  Atticus knows that the Cunninghams will target his client, so he plans to sit up all night with... Atticus brings the light to the courthouse jail so that he can protect Tom Robinson.  Atticus learns that Tom Robinson, his client, is in danger.  A group of white men want to prevent the trial and lynch Robinson. He is warned by a small group of men that appear at his house.  He refuses to back down.  Atticus knows that the Cunninghams will target his client, so he plans to sit up all night with Jim if that’s what it takes to protect him.  Atticus tells the men that he will make sure his client gets his fair shake at the law.  “Link, that boy might go to the chair, but he’s not going till ...