PRE TEST Flashcards
Once carbon dioxide is absorbed by the seawater, an ample amount of chemical reactions will occur that increases the concentration of hydrogen ions. If this will continue, what will be the effect in the seawater?
Acidification due to increasing of hydrogen ions causing the water to become too acidic.
Which among the choices would recognize the importance of chemistry behind the products that we are using daily?
Chemistry focuses on the components of materials and its reaction to other materials that lead to many products.
Which of the following is a chemical property of water?
Reacts violently with sodium and expands when it freezes
Fire problems are being rampant in the environment in NCR because of the large number and setting of houses. What is the most evident physical property of matter that contributed to this problem?
Flammability and combustibility of materials
What possible separation technique is used if the miscible liquids have asignificant difference in boiling points generally 70°C?
SIMPLE DISTILLATION
Which separation technique is used in a mixture of immiscible liquids?
DECANTATION
In what manner is chemistry of immediate use to a farmer?
USE OF FERTILIZERS
How will you know if the soap you are choosing is good or not good for bathing?
Check the Total Fatty Matter percentage (TFM %).
Which of the following sets of properties are all extensive properties of a substance?
MASS, VOLUME, HEIGHT
It happens when a substance undergoes changes in its composition.
CHEMICAL CHANGE
Which should NOT be considered in buying products?
COMMERCIAL ADS OF THE PRODUCTS
Kerosene and water are the components of the mixture that can be separated using decantation. What is the basis of separating the components of mixtures using this technique?
DENSITY
To remove salt from the mixture of ground mothball and salt, which method is applicable?
SUBLIMATION
Which group contains an element, a mixture and a compound?
SEAWATER, LEAD, AMMONIA
Which physical test can be used to distinguish between a solution and a colloid?
TYNDALL EFFECT TEST
Which type of mixture is used in separating its components by decantation?
HETEROGENEOUS MIXTURE
With the current situation, which best option below will help you ensure safety in choosing and buying chemical products that are sold online?
SEARCH FOR THE MATERIAL SAFETY DATA SHEET OF THE PRODS
Which of the following is the active component of detergent that do the job of linking water and dirt?
SURFACTANT
Forensic scientist uses ink to solve crimes by matching documents or stains found in a crime scene to the marker or pen that belongs to a suspect. What separation technique could be used?
CHROMATOGRAPHY
Oil spill is evident in bodies of water. This is due to oil companies that discharge their wastes into the bodies of water. Which among these properties does NOT contribute to this phenomenon?
POLARITY
During birthdays, spaghetti has been the most requested food at home. You are told to remove the pasta from the pan with hot water. As a STEM student, what separation technique will you apply?
Use a strainer to easily separate the pasta from the hot water.
When a liquid is distilled, tiny glass beads are sometimes place in the distillation flask. What is the reason for using the beads? The beads
ALLOWS SMOOTH BOILING
What separation technique is useful in determining the antibodies that could fight diseases and viruses?
CHRIMATOGRAPHY
A glowing match was dropped into a dry gas jar containing one gas only. The match (but not the gas) caught a light. Which gas is most likely present in the jar?
OXYGEN
