Answer:
Reducing sugars are absent
Explanation:
Benedict's solution is an substance used in testing sugars. It is mixture of sodium carbonate, sodium citrate and copper(II) sulfate pentahydrate. It can be used instead of Fehling's solution in testing for the presence of reducing sugars.
Reducing sugars contain the -CHO group. If there is no colour change after the addition of Benedict's solution, then we can conclude that reducing sugars are absent.
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Answer:</h3>
382.63 K
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Explanation:</h3>
We are given;
- Volume of Iodine as 71.4 mL
- Mass of Iodine as 0.276 g
- Pressure of Iodine as 0.478 atm
We are required to calculate the temperature of Iodine
- We are going to use the ideal gas equation;
- According to the ideal gas equation; PV = nRT, where R is the ideal gas constant, 0.082057 L.atm/mol.K.
T = PV ÷ nR
But, n, the number of moles = Mass ÷ Molar mass
Molar mass of iodine = 253.8089 g/mol
Thus, n = 0.276 g ÷ 253.8089 g/mol
= 0.001087 moles
Therefore;
T = (0.478 atm × 0.0714 L) ÷ (0.001087 moles × 0.082057)
= 382.63 K
Thus, the temperature of Iodine in Kelvin is 382.63 K
There are different chemical agents which are used to study the heart rate of frog. Generally Ringer's solution is used to study frog's heart simulation. At different temperature, frogs heart speeds up or slows down while using Ringer's solution at experiment. Ringer's solution is mixture of salt solution which comprises of NaCl, KCl, CaCl2 and Na2CO3. Sometimes other chemicals like MgCl or antibiotics are also used as addition in Ringer's solution.
This solution is chiefly used to study in vitro experiments on organs and tissues like frog's heart.
Ringer's solution at 23 degree Celsius for normal heart rate
Ringer's solution at 32 degree Celsius, heart rate speed up and
Ringer's solution at 5 degree Celsius, heart rate slows down.
other chemicals also have significant effect in heart rate,
For example, Calcium ion in excess will slow down the heart rate, Atropine increases heart rate and digitalis slows down the heart rate.
You can see my previous answer to this very same question on brainly.com/question/11374210.
The answer is: option D. Response to environment.
Explanation:
As explained, plants (organisms in general) respond to the stimulus provided by the environment.
Such behavior is named tropism. Tropism may be positive or negative.
When the plant's stem bends toward the window, it is showing positive phototropism, which means that the plant growth response to light such that the stems bend toward light, permiting the leaves to receive more light.
I also mention that while the plant's stems posses positive phototropism they posses negative gravitropism and the roots posses positive gravitropism.
Gravitropism is the response of the plant growth to gravity.
Stems grow away from gravity meaning that this is negative gravitropism, but roots grow toward gravity which is positive gravitropism