The Mole and Atomic Mass | Chemistry | Visionlearning
The mole fraction, X, of a component is the ratio of its molar amount to the total . Use the equation relating boiling point elevation to solute molality to solve this body fluids of fish and other cold-blooded sea animals that live in these oceans). .. prevent the ions from behaving as totally independent particles (Figure 11). SCH3U Grade 11 Chemistry In this experiment you will allow sodium bicarbonate (baking soda) to react with The theoretical yield can be calculated by using the mole and mass ratios obtained from the balanced equation for the reaction. To gain an understanding of mass relationships in chemical reactions . PASCO Digital Library contains hundreds of free experiments and lab Animal Behavior stimuli and determine if there is a significant change in their behavior. Students use temperature, pH, and conductivity sensors to explore chemical . Use a temperature sensor to determine the mole ratio between the reactants.
7: Mole Ratios and Reaction Stoichiometry (Experiment) - Chemistry LibreTexts
This approach is still used by scientists today to figure out the relative mass of an atom from one element compared to the mass of an atom from a different element. Comprehension Checkpoint Avogadro is credited with proposing that all matter is made up of atoms. Inan Austrian chemist named Josef Loschmidt came up with a way of estimating that number.
Working with the assumptions of kinetic-molecular theory on the size of gas molecules and the distance between them see our module on Kinetic-Molecular TheoryLoschmidt estimated the number of particles in one cubic centimeter of a gas to be 1. By the start of the 20th century, this enormous number was given a new name. The name took off among chemists because Perrin used it in his popular chemistry books. Around the same time, the concept of having a standard number of particles correspond to the mass of a solid was being developed by German chemists.
The scientists called this concept the Kilogrammemolekuel, which was soon shortened to "mole. Since the early 20th century, physicists had been developing a unified atomic mass scale—basically, a way for comparing the mass of an atom from one element to the mass of an atom from another element. The atoms of all other elements were then compared to this 16O reference. In place of 16O, the group decided to use the most common isotope of carbon, carbon 12Cas the reference. The group decided that the mass of one 12C atom would be set as 12 atomic mass units amuand the atomic mass of the atoms of all other elements would be determined relative to 12C—the standard we still use today.
To link the relative atomic mass scale to both absolute mass and moles, the group defined one mole as equal to the number of 12C atoms in 12 grams of 12C. The number of 12C atoms in 12 grams was experimentally determined to be 6. Comprehension Checkpoint The mole is a unit of measure in the metric system.
In the case of 12C, we can see that the value for its molar mass and atomic mass both equal 12, although the units are different. While atomic mass is measured in amu, molar mass is measured in grams per mole. Electrocommunication Electrocommunication is a rare form of communication in animals.
It is seen primarily in aquatic animals, though some land mammals, notably the platypus and echidnassense electric fields that might be used for communication. These fish use an electric organ to generate an electric field, which is detected by electroreceptors.
Differences in the waveform and frequency of changes in the field convey information on species, sex, and identity. These electric signals can be generated in response to hormones, circadian rhythms, and interactions with other fish. Some predators, such as sharks and rays, are able to eavesdrop on these electrogenic fish through passive electroreception.
For more on the mechanism for touch, see Somatosensory system and Mechanoreceptors Touch is a key factor in many social interactions. Here are some examples: In a fight, touch may be used to challenge an opponent and to coordinate movements during the fight. It may also be used by the loser to indicate submission.
Mammals often initiate mating by grooming, stroking or rubbing against each other. This provides the opportunity to apply chemical signals and to assess those excreted by the potential mate.
- Digital Library
- Animal communication
- The Mole and Atomic Mass
Touch may also announce the intention of the male to mount the female, as when a male kangaroo grabs the tail of a female. During mating, touch stimuli are important for pair positioning, coordination and genital stimulation. Touch is widely used for social integration, a use that is typified by the social grooming of one animal by another. Social grooming has several functions; it removes parasites and debris from the groomed animal, it reaffirms the social bond or hierarchical relationship between the animals, and it gives the groomer an opportunity to examine olfactory cues on the groomed individual, perhaps adding additional ones.
This behaviour has been observed in social insects, birds and mammals.
Some ant species recruit fellow workers to new food finds by first tapping them with their antennae and forelegs, then leading them to the food source while keeping physical contact. Another example of this is the waggle dance of honey bees. Prolonged physical contact or huddling also serves social integration. Huddling promotes heat exchange, together with the transfer of olfactory or tactile information. Some organisms live in constant contact in a colony, for example colonial corals.
When individuals are linked tightly in this way an entire colony can react on the aversive or alarm movements made by only a few individuals. In several herbivorous insect nymphs and larvae, aggregations where there is prolonged contact play a major role in group coordination. These aggregations may take the form of a procession or a rosette. Seismic communication Seismic communication is the exchange of information using self-generated vibrational signals transmitted via a substrate such as the soil, water, spider webs, plant stems, or a blade of grass.
This form of communication has several advantages, for example it can be sent regardless of light and noise levels, and it usually has a short range and short persistence, which may reduce the danger of detection by predators. The use of seismic communication is found in many taxa, including frogs, kangaroo rats, mole rats, bees, nematode worms, and others.
Tetrapods usually make seismic waves by drumming on the ground with a body part, a signal that is sensed by the sacculus of the receiver.
The sacculus is an organ in the inner ear containing a membranous sac that is used for balance, but can also detect seismic waves in animals that use this form of communication.
Vibrations may be combined with other sorts of communication. Thermoreception A python top and rattlesnake illustrating the positions of the pit organs.
Red arrows indicate the pit organs whereas black arrows indicate the nostril. The accuracy of this sense is such that a blind rattlesnake can target its strike to the vulnerable body parts of a prey animal. Most superficially, pitvipers possess one large pit organ on either side of the head, between the eye and the nostril loreal pitwhile boas and pythons have three or more comparatively smaller pits lining the upper and sometimes the lower lip, in or between the scales.
Those of the pitvipers are the more advanced, having a suspended sensory membrane as opposed to a simple pit structure. Within the family Viperidaethe pit organ is seen only in the subfamily Crotalinae: It senses infrared signals through a mechanism involving warming of the pit organ, rather than chemical reaction to light. This infrared perception may be used in detecting regions of maximal blood flow on targeted prey.
Chapter 1.7: The Mole and Molar Mass
Autocommunication[ edit ] Autocommunication is a type of communication in which the sender and receiver are the same individual. The sender emits a signal that is altered by the environment and eventually is received by the same individual.
The altered signal provides information that can indicate food, predators or conspecifics. Because the sender and receiver are the same animal, selection pressure maximizes signal efficacy, i. There are two types of autocommunication. The first is active electrolocation found in the electric fish Gymnotiformes knifefishes and Mormyridae elephantfish and also in the platypus Ornithorhynchus anatinus. The second type of autocommunication is echolocationfound in bats and toothed whales.
Functions[ edit ] There are many functions of animal communication. However, some have been studied in more detail than others. Animal communication plays a vital role in determining the winner of contest over a resource. Many species have distinct signals that signal aggression or willingness to attack or signals to convey retreat during competitions over food, territories, or mates. Two Red Deer roaring most likely to establish dominance during a rut.
However, males also use loud roaring to keep track of harems of females. Animals produce signals to attract the attention of a possible mate or to solidify pair bonds. These signals frequently involve the display of body parts or postures. For example, a gazelle will assume characteristic poses to initiate mating. Mating signals can also include the use of olfactory signals or mating calls unique to a species. Animals that form lasting pair bonds often have symmetrical displays that they make to each other.
Famous examples are the mutual presentation of reeds by great crested grebes studied by Julian Huxleythe triumph displays shown by many species of geese and penguins on their nest sites, and the spectacular courtship displays by birds of paradise. Signals used to claim or defend a territory, food, or a mate. Many animals make "food calls" to attract a mate, offspring, or other members of a social group to a food source.
Perhaps the most elaborate food-related signal is the Waggle dance of honeybees studied by Karl von Frisch. One well-known example of begging of offspring in a clutch or litter is altricial songbirds. Young ravens will signal to older ravens when they encounter new or untested food.