Дръжте се топло с Samsung Galaxy
На скъпата 38-годишна блондинка, която всички познаваме, се случиха някои доста интересни неща. Тя обичаше да снима моментите от живота си и да ги споделя със своите приятели в социалните мрежи. Но един ден, тя направи сериозна грешка и снима как верфът изгаря, ползвайки Samsung Galaxy телефон. След като сподели снимката в Twitter-а си, тя не осъзна, че публикува видео, в което кърмието й прелива надълго и нашироко. Цялата история може да прочетете в повече.
Лоша репутация на полицията в Канзас, заснета на Tiktok.
%Николай: Безотговорно поведение на ръководителя на полицията в Канзас, съветващ се с Tiktok.
%Мария: Неприемливо и неетично поведение от страна на ръководителя на полицията в Канзас, което се разпространява в Tiktok.
%Петър: Срамежлив ръководител на полицията в Канзас, извличащ се в Tiktok.
%Ива: Неморален началник на полицията в Канзас, разкриващ се в Tiktok.
%Иван: Ужасна вест за началника на полицията в Канзас, изявяващ се в Tiktok.
The standard enthalpy change for a reaction can be determined experimentally by measuring the heat exchanged with the surroundings using a calorimeter. This method involves measuring the temperature change of the surroundings when the reaction occurs.
To determine the enthalpy change of a reaction using a calorimeter, the following steps are typically followed:
1. Prepare the calorimeter: The calorimeter is usually a container made of a thermally-insulated material to minimize heat exchange with the surroundings. The calorimeter is filled with a known quantity of water to act as the surroundings.
2. Measure the initial temperature: The initial temperature of the water in the calorimeter is measured accurately.
3. Carry out the reaction: The reactants are mixed in a separate container and transferred into the calorimeter. As the reaction occurs, heat is released or absorbed and is transferred to the water.
4. Measure the final temperature: The final temperature of the water in the calorimeter is measured accurately.
5. Calculate the heat exchanged: Using the equation q = mcΔT, where q is the heat exchanged, m is the mass of water, c is the specific heat capacity of water, and ΔT is the change in temperature, the heat exchanged between the reaction and the water can be calculated.
6. Calculate the enthalpy change: The enthalpy change of the reaction can be calculated using the equation ΔH = q/n, where ΔH is the enthalpy change, q is the heat exchanged, and n is the number of moles of reactant or product involved in the reaction.
It should be noted that the reaction should be carried out under constant pressure conditions (typically atmospheric pressure) to determine the standard enthalpy change. Additionally, the heat capacity of the calorimeter itself should be determined and taken into account in the calculations.
Overall, using a calorimeter allows for the determination of the heat exchanged in a reaction, which can be used to calculate the enthalpy change and determine the energetics of the reaction.