A calorimeter contains 500 g of water at 25°C.....
the temperature of the water inside the calorimeter is 39.4°C.....
The specific heat of water is 4.18 J/g-°C.
energy needed to heat the water = specific heat * mass * temp difference
= 4.18 J/g-°C * 500 g * (39.4°C - 25°C)
= 4.18*500*14.4
= 30096J
or approx. 30kJ
Answer:
c) a buffer solution with pH= 5
Explanation:
The equation of hydrolisis of water is:
1x10⁻¹⁴ = [H⁺] [OH⁻]
That means if we know [H⁺] we can find hydroxide-ion concentration and vice versa.
a) HCl 0.1M = [H⁺] = 0.1M;
1x10⁻¹⁴ / [H⁺]
1x10⁻¹⁴/ 0.1M = [OH⁻]
1x10⁻¹³M = [OH⁻] hydroxide- ion concentration.
b) 0.1M H₂SO₄ = 0.2M [H⁺]
1x10⁻¹⁴/ 0.2M = [OH⁻]
5x10⁻¹⁴M = [OH⁻]
c) pH = 5.
[H⁺] = 1x10⁻⁵M
1x10⁻¹⁴/ 1x10⁻⁵M = [OH⁻]
1x10⁻⁹M = [OH⁻]
d) pOH = 12.
[OH⁻] = 1x10⁻¹²M
That means risht answer is:
<h3>c) a buffer solution with pH= 5</h3>
Answer:
Endoplasmic reticulum.
Explanation:
Second messengers are known as intracellular signaling molecules released from the cell in response to exposure to extracellular signaling molecules. Second messenger activate physiological changes at a cellular level, for example proliferation, migration, differentiation, survival, and apoptosis.
Calcium ions are hydrophilic, water-soluble molecules. They are present in intracellular component know as endoplasmic reticulum and quickly released when needed. They are necessary for many important functions including fertilization, muscle contractions, and neurotransmitter release.
speed and direction in which an object is moving. both speed and direction of motion. is a vector. two or more velocities add by velocity addition.
