## pnicole 3 years ago When 155 mL of water at 26 C is mixed with 75 mL of water at 85 C, what is the final temperature? (Assume that no heat is lost to the surroundings; d of water 1.00 g/mL.)

1. pnicole

Someone please help, I really don't know where to begin or how to solve this. :( Even just an equation will do.

2. wach

I'm not that familiar with this exact calculation, so excuse me if I'm wrong. The equation for this should be : ( Volume1 * Temp1) + (Volume2 * Temp2) / (Volume1 + Volume2) = Final temp

3. NoelGreco

The amount of heat a substance gains or loses is governed by the following formula: \[Q=mc \Delta T\] Where Q is the heat lost or gained, m is the mass in kg, c is the specific heat of the substance (c-1.00 for water), and deltaT is the change in temperature. Since the heat gained by the cold water is = to the heat lost by the warm water the two Qs can are equal. Thertefore: \[m _{c} \Delta T _{c }=m _{w}\Delta T _{w}\] The c and w subscripts are for the cold and warm water. Since both waters are at the same final temperature: \[m _{c}(T _{f}-26)=m _{w}(85-T _{f})\] where T sub f is the final temp for both masses of water. The expressions in the parentheses were switched because you always want a positive delta T.

4. pnicole

Thank you so much!