It speeds up chemical reactions
Answer:
The amount of heat required to raise the temperature of a 32g sample of water from 8°C to 22°C is 1,874.432 J
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).
Between heat and temperature there is a direct proportional relationship. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat and the mass of the body. So, the equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
- c= 4.184

- m= 32 g
- ΔT= Tfinal - Tinitial= 22°C - 8°C= 14°C
Replacing:
Q= 32 g* 4.184
*14 °C
Solving:
Q= 1,874.432 J
<u><em>The amount of heat required to raise the temperature of a 32g sample of water from 8°C to 22°C is 1,874.432 J</em></u>
The correct answer is that 1.125 mol of NaOH is available, and 60.75 g of FeCl₃ can be consumed.
The mass of NaOH is 45 g
The molar mass of NaOH = 40 g/mol
The moles of NaOH = mass / molar mass
= 45 / 40
= 1.125
Thus, 1.125 mol NaOH is available
3 NaOH + FeCl₃ ⇒ Fe (OH)₃ + 3NaCl
3 mol of NaOH react with 1 mol of FeCl₃
1.125 moles of NaOH will react with x moles of FeCl₃
x = 1.125 / 3
x = 0.375 mol
0.375 mol FeCl₃ can take part in reaction
The molar mass of FeCl₃ is 162 g/mol
The mass of FeCl₃ = moles × mass
= 0.375 × 162
= 60.75 g
Thus, the amount of FeCl₃, which can be consumed is 60.75 g
Answer:
A compound
Explanation:
Chemical compound can be regarded as any substance made up of identical molecules which consists atoms of two or more than two chemical elements. For example four hydrogen atoms bonds with a carbon atom to give methane molecule which is a compound. It should be noted that A compound is a new substance with unique chemical and physical properties formed when two or more elements are chemically bonded during a physical reaction.
Answer:
a) pH = 11.5
b) pH= 3
Explanation:
a) lets calculate the number of moles of each reactant
moles of HCl = 32/1000 * 0.32 = 0.01024 mole
moles of NaOH = 42/1000 * 0.32 = 0.01344 moles
1 moles of HCl reacts with 1 moles of NaOH , so 0.01024 mole of HCl should react with 0.01024 moles of NaOH , but there is some excess NaOH.
excess NaOH= 0.01344 -0.01024 = 0.0032 moles
[H+]=
pH= -log [3.125*10^-12) = 11.5
b) moles of NaOH = 0.00924
excess HCl present = 0.01024 - 0.00924 =.001
so excess [H+] = 0.001
pH= -log( 0.001) = 3