<h3>
Answer:</h3>
1379.4 Joules
<h3>
Explanation:</h3>
- The quantity of heat is calculated multiplying the mass of a substance by heat capacity and the change in temperature.
Therefore;
Quantity of heat = Mass × specific heat capacity × Change in temperature
Q = mcΔT
In this case;
The substance dissolved in water gained heat while water lost heat energy.
Thus, Heat gained by the substance = heat lost by water
Heat associated with the water
Mass of water = 75 g
Change in temperature = 4.4°C
Specific heat capacity = 4.18 J/g·⁰C
Heat = mcΔT
= 75 g × 4.18 J/g·⁰C × 4.4 °C
=1379.4 Joules
C; The Valence electrons spend more time around the atom of F
Wind affects pollution because it moves it, the wind carries the pollution and move it somewhere else
Answer:
0.278 mol HCl
Explanation:
We currently have 185.0 mL of a 1.50 mol/L solution of HCl. We want to find the number of moles there are.
Based on the given information, our volume is 185.0 mL and our molarity is 1.50. Because molarity is defined as moles / Litre, we can easily find the moles given volume by multiplying molarity by volume.
First, though, we must convert millilitres to litres. There are 1000 mL in 1 L, so divide 185.0 by 1000:
185.0 / 1000 = 0.185 L
Now, multiply 0.185 by 1.50:
0.185 L * 1.50 mol/L = 0.278 mol HCl
Thus the answer is 0.278 mol HCl.
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Answer:
you must add 50 mL
Explanation:
Hi
KOH is a strong base and by adding 100mL 0.05M you will have an amount of 5 millimol.
NaCN is a base and by adding 50 mL 0,150 M you will have an amount of 7,5 mmol.
HCl is a acid and by adding 200 mL 0,075 M you will have an amount of 15 mmol.
The acid reacts with the bases leaving 2.5 mmol unreacted.
Na3PO4 is a base and by adding 50 mL 0,1 M you will have an amount of 5 mmol.
The 2.5 mmol of acid react with the base PO4 ^ -3 forming a regulatory solution of PO4 ^ -3 and HPO4 ^ -2 of pKa 2.12
5 mmol of acid (HNO3) must be added to obtain a regulatory solution formed by the same amount of HPO4 ^ -2 (2.5 mmol) and H2PO4 ^ -1 (2.5 mmol) with pKa 7.21
Considering a quantity of 5 mmol of HNO3 of concentration 0.1 M, 50 mL must be added.
To calculate the pH of the regulatory solution you should consider pH = pKa × Ca / Cb pH = 7.21 × 2.5 / 2.5 = 7.21 Being in the same solution the volume is the same and can be simplified to achieve a faster calculation.
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