Answer:
b) pH = 9.25
Explanation:
- NH4+(aq) + H2O(l) ↔ NH3(aq) + H3O+(aq)
- NH3 + H2O ↔ NH4+ + OH-
- 2 H2O ↔ H3O+ + OH-
⇒ Kb = [ NH4+ ] * [ OH- ] / [ NH3 ] = 1.86 E-5......from literature
mass balance NH4+:
⇒ M NH4+ = [ NH4+ ] - [ OH- ]
∴ [ NH3 ] ≅ M NH4+ = 0.26 M
⇒ Kb = (( 0.26 + [ OH- ] )) * [ OH- ] / 0.26 = 1.86 E-5
⇒ 0.26 [ OH-] + [ OH- ]² = 4.836 E-6
⇒ [ OH- ]² + 0.26 [ OH- ] - 4.836 E-6 = 0
⇒ [ OH- ] = 1.859 E-5 M
⇒ pOH = - Log ( 1.859 E-5 )
⇒ pOH = 4.7305
⇒ pH = 14 - pOH = 9.269
There are 3 significant figures in this value, all values before and after the decimal point are significant. As there is a decimal point, the zeros trailing are also significant.
The food has 23629.64 cal
<h3>Further explanation</h3>
Given
mass = 1000 g of water
temperature increases 23.65 * C
Required
The energy of the food
Solution
Heat absorbed by water :
Q = m . c . Δt
Q = 1000 g x 4.184 J/g°C x 23.65 °C
Q = 98951.6 J
1 Joules = 0.2388 Calories
98951.6 J = 23629.64 cal
Answer:Releasing insulin to decrease blood sugar and releasing glucagon to increase blood sugar
Explanation: homoestasis is the process by which the body keep it's internal environment constant, regardless of change in the external environment. The human body has a normal range in which it's system operates and it uses homoestasis to keep these at constant.
Homeostasis could be positive or negative. It usually involves a sensor which detects the changes in the body and passes the information to the control center, a control center which receive information from the sensor and sends signals to the effectors and the effector which acts on the information sent by the control center to effect normalcy.
In this case, when a person eats food,he gets glucose. Blood sugar most be kept at constant so the endocrine system release the hormone insulin. Insulin helps to convert glucose to glycogen, which is the form it can be stored in the liver
When the blood sugar levels is low, the brain which is the control center causes glucagon to be released . This hormone converts glycogen to glucose
I would say C. petroleum
A is wrong
B is impractical for "mainly used"
D thats too expensive
