Unit 3 Fluids Lab Report

I. LIQUID - Identification of an Unknown Liquid: Using the physical properties of Solubility, Density, and Boiling Point.

Procedure: I used a ruler, thermometer, and scale to take measurements. I used a graduated cylinder, short step pipet, scale, and ruler to determine volume and density. I used a volumetric flask, graduated pipet, pipet bulb, scale, and glass beaker to determine concentrations and densities of various dilutions.

The objective of the experiment “Keeping it Liquid” was to figure out what it takes to keep a compound in a liquid form which caused a phase change. A phase change is when a substance changes from one state or phase to another. There are three main phases that normally occur and they are called Evaporation, Deposition, and Melting. Evaporation is where a liquid changes to a gas. An example of evaporation is when water drops form on the glass of a cold drink on a warm day. Deposition is where a gas vapor goes directly into the solid phase without becoming a liquid first. An example of Deposition often occurs on windows during the winter months. While Melting is where a solid turns into a liquid. Melting occurs when ice turn into a liquid when

In this lab experiment our main focus was to get skillful in using tools such as the metric ruler, balances, thermometer, and graduated cylinder to capture measurements of length, mass, temperature and volume. Additionally, this lab helped us to become more familiar with the uncertainty of measurements, as well as becoming efficient with rounding our measurements to the correct numbers of significant figures. Our results are measured consistently with rounding to the closest answer we could possibly acquire as the data can tell you.

11. Tare the scale by pressing the Φ/T button so that the scale reads 0.0 g.

The human sense of touch is known as the somatic or somatosensory system. The skin is the biggest and most complex organ in the somatosensory system.The somatosensory system permits the human body to experience pressure, texture, temperature, and pain, and to see the position and development of the body's muscles and joints.The receptor cells in the skin can be separated into three useful classifications: mechanoreceptors that sense pressure and surface, thermoreceptors that sense temperature, and nociceptors that sense pain. Thermoreceptors distinguish changes in temperature utilizing two sorts of receptor cells: warm and cold. Thus, thermoreceptors on the skin detects the temperature signal using two specific receptors cell: warm and cold.

Ionic compounds are soluble in water to a certain point depending on the compound. The level of solubility changes among different compounds. Some ionic compounds can completely dissolve in water and appear to be a homogeneous mixture. Although, some ionic compounds dissolve very little, and could be considered insoluble, since it does not dissolve fully. Depending on the compound, the level of solubility can be high or low. However, ionic compounds could dissolve to a certain degree. If the solution appears to be a heterogeneous mixture, many may assume through visual representation that it may be insoluble. As stated previously, the smallest amount of solubility should be considered. To confirm whether or not the substance is soluble, observe the efficiency when conducting electricity. Due to practical reasons, the slightest solubility could be considered insoluble by people.

2. In order to calculate the density of a solid or liquid sample, what measurements are needed?

The $TM$ is composed of three different layers, namely the uveal meshwork, the corneoscleral meshwork and the juxtacanalicular meshwork ($JCT$). As intercelular areas are considerable, the uveal meshwork does not present much resistance to $AH$ outflow. The second layer presents lamellae covered by endothelium-like cells, their intracellular spaces are narrovwer and thus, increase the flow resistance. The juxtacanalicular meshwork is an irregular tissue and is the major cause of resistance to flow. It lies directly the inner wall of endothelial cells from the $SC$ \cite{llobet2003understanding}.

Table 2: Consists of color extract taken from a red cabbage for a natural indicator. The pH reading that was measured by using the pH meter and the result of the pH reading to determine whether the solution was acidic or basic.

In the third stage of this experiment, the density of a liquid was determined and compared to known standards. A 100ml beaker was filled to about half-full with room-temperature distilled water. The temperature of the water in ◦C was recorded in order to compare to known standards later. A 50ml beaker was then weighed on a scale in order to determine mass and recorded. A sample of the distilled water with an exact volume of 10ml was then placed in the 50ml beaker using a volumetric pipette. The 50ml beaker with the 10ml of water was then weighed again and the initial mass of the beaker was subtracted from this mass to obtain the mass of the 10ml of water. With the volume and the mass of the water now known, density was calculated using d = m/V and recorded in g/ml. This process was then repeated to check for precision and compared to standard values to check for accuracy. Standard values were obtained from CRC Handbook, 88th Ed.

It used mass, temperature, length, volume, density, and making a dilute solution. I learned the importance as well as the difficulty of making proper measurements in a lab setting. If one measurement is off, it will throw the entire equation off. This will give either incorrect or inaccurate results.

2. (5 pts) List and explain the names and affiliations of the various characters/stakeholders in this story – I’m looking for us to use the story to map out the complexities that are generally associated with solving public health puzzles – the stakeholders you list and explain here should apply to many of the cases we consider going forward.

The weight of each 50ml beaker (used for weighing the mass of dissolved Potassium chloride after the evaporation of water) should be recorded. If the experimenter were to weigh the mass of one beaker and take it as a default mass, the latter may be a source of error.

The two independent variables were luminant cue patches (light cue, dark cue and equiluminant cue) and location of the cue and target (valid side with cue and target on same side and invalid side with cue and target on opposite sides). The dependent variable was participants’ reaction time in millisecond.