Answer:
54.99% yield
Explanation:
percent yield is just the amount you obtained over the amount expected times 100%.
(experimental value/theoretical value) x 100%
= (107.9 g/196.2 g) x 100%
=54.99% yield
Answer:
PULLIN OUT THE COUPE AT THE LOT?
Explanation:
TOLD EM F*&*& 12 F*(&*(& SWAT
Answer:
a b d
these are part of an ecosystem or can be
Complete question is;
Which statements accurately describe the evidence that scientists gather using fossils? Check all that apply.
A) The fossil record can be used to date rocks.
B) Living things with many cells have always lived on Earth.
C) Simple organisms are found only in young rocks.
D) Geologists study ancient remains of plants and animals.
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates.
Answer:
A) The fossil record can be used to date rocks
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates
Explanation:
In scientific research, fossils are sometimes referred to as animals and plant. Now, in studying records of fossils, it will be easy to know the length of existence of living things on the Earth. Also, we can be able to identify the manner in which different relationships exists between plants and animals by predicting their lifestyles, location of their habitation e.t.c which can be used to predict the old time climates.
Looking at the options given in relation to the explanation given, options A, E & F are correct
Answer:
Delta H for endothermic reaction is positive-True. This is because an endothermic reaction absorbs heat energy, therefore more energy is retained inside the product of the reaction system than the reactants, as the value of deltaH is greater than Zero.
Delta H for an exothermic reaction is positive. This is false. Because in an exothermic reaction heat is liberated to the surrounding environment. therefore the value of thus the outer environment contains more energy than the internal environments, thus the enthalpy of the reactants is greater than that of the products.
when the energy is transferred as heat from system to surroundings, deltaH is negative. True . This is true because the surrounding environment gain heat energy, (positive)while the system loses it,(negative) therefore delta H is negative.
when the energy is transferred as heat from surroundings to system, deltaH is negative. False. This is positive, because now the environments loses heat, (negative) while the systems gains heat,( positive) therefore delta H of the system is positive. endothermic
the evaporation of water is an exothermic process-False, This is an endothermic reaction in which water molecules need to gain heat energy from the surrounding environments to increase the average kinetic energy of collusion to escape the intermolecular forces to escape as steam.
Combustion reaction is exothermic. True., because heat energy is transferred to the surrounding from the internal system. The energy needed for the formation of new bonds in the products is higher than the energy for breaking of original bonds in the reactants. Thus more heat is liberated.
Explanation:
