Answer:
1. An ancient study or art which attempted to combine science and philosophy to solve worldly problems Alchemy
2. A homogeneous mixture of elements with metals to form metallic solids Alloy.
3. The simplest unit of an element that still retains the properties of that element compound Atom
4. Two or more elements joined together such that the elements have lost their individual identity Compound
5. A primary substance that cannot be divided into separate substances element Element.
6. The group of elements that are good conductors of electricity and heat Metals
7 . The group of elements that are poor conductors of electricity and heat Non metal
Answer:
B. False
Explanation:
the reaction is
H₂0 + O₂ = H₂O
as addition of oxygen means burning in the system which means heating or energy is necessary for the reactants. SO the reaction is spontaneous and exothermic .
As according to second law of thermodynamics
the change in enthalpy is greater than or equal to zero when the reaction is spontaneous, so enthalpy will increase in the above reaction.
H2 burning in O2 to form H2O (l) is an example of a system where the entropy of the universe increases.
Answer:
what is wright there is no question
1. The hypothesis for this is experiment is that the 50:50 of methanol-water mixture will not turn to solid when the temperature reaches to -40°C.
2. The procedure for this is measuring equal volumes of water and methanol using the graduated cylinder. You can measure 100 mL of water and 100 mL of methanol using the graduated cylinder. Then, mix them in the beaker. Next, measure 200 mL of water, and another 200 mL of methanol. Don't mix them. Also, make a 60:40 mixture by measuring 120 mL of water and 80 mL of methanol, then mix them together. Place them all in the refrigerator at the same time. Record the time when they would freeze to solid.
3. The controls for this experiment are the 200 mL water alone, and the 200 mL methanol alone.
4. The independent variable in here is the time, while the dependent variable is the temperature of the mixtures.
5. If the hypothesis turns out to be true, then all the mixtures prepared should freeze and become solid after a certain period of time, with the exception of the 50:50 mixture. The 50:50 mixture should still remain as a liquid even when left overnight.
