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How do you find moisture content in sand?
Moisture content in sand can be determined by taking a sample, drying it in an oven, and then weighing it before and after to calculate the difference in weight. The moisture content is expressed as a percentage of the weight of water compared to the dry weight of the sample.
What is sulphated ash?
The sulphated ash test is an analytical test for determining the inorganic content of a sample by weight. The sample ( usually 1g) is accurately weighed into a platinum, silica crucible that has been previously ignited, cooled and weighed. The sample in the crucible is then subjected to sulphuric acid (usually 1mL) and charred at a low temperature without causing ignition of the sample until there are no more white fumes given off. The crucible with the charred sample is then placed in a furnace (temperature is dependent on monograph but typically it can be from 600 to 900 degrees celcius) until all organic matter has been burnt off. The crucible is cooled and re-weighed. The difference in sample weights being the sulphated ash content remaining. Some monographs require the sample to be re-ashed until a constand weight has been achieved. The remaining inorganic matter is typically metal oxides from most samples.
What is the percent recovery of the sample if a student dissovles 1.00 g of a mixture of salicylic acid and copper sulfate and recovers 0.49 g and 0.28 g respectively?
The percent recovery for salicylic acid is 49% (0.49 g recovered out of 1.00 g dissolved) and for copper sulfate is 28% (0.28 g recovered out of 1.00 g dissolved).
Which type of weathering only affects the size of a sample?
Mechanical weathering, also known as physical weathering, only affects the size and shape of the rock without changing its mineral composition. This can be caused by processes such as freeze-thaw cycles, root wedging, and salt crystal growth.
Why is the collected soil sample dried before weighing in soil analysis?
because the hydrogen cells in the H2O will give the soil an unbalance when being wheighed because the hydrogen cells in the H2O will give the soil an unbalance when being wheighed
Sample A weighed 3 ounces Sample B weighed 814 thousandths of an ounce more than Sample A What decimal should you use to record the weight of Sample B?
.00814
What is Weighing by difference?
Weighing by difference involves weighing a sample both before and after a process to determine the mass change due to the process. The difference in mass is the desired quantity being measured. This method is commonly used in analytical chemistry for accurate determination of constituents in a sample.
Why the content in crucible is not weighed while it is still hot?
The content in a crucible is not weighed while hot because heat can cause air currents and thermal expansion, leading to inaccuracies in measurement. Additionally, any moisture or volatile substances may evaporate or escape, affecting the mass of the sample. Weighing when the crucible is cool ensures a stable and accurate measurement of the substance.
Why should a piece of laboratory tissue or tongs be used to handle a sample container to be weighed?
Using laboratory tissue or tongs to handle a sample container when weighing it helps to prevent contamination of the sample. Any oils, dirt, or residues on your hands could transfer to the container and affect the accuracy of the measurement. Additionally, using these tools helps ensure the sample remains untouched by any external substances.
How is fat content determined by soxhlet method?
The Soxhlet method for determining crude fat content is a lengthy process requiring up to a day for a single analysis. The solvent extraction step alone takes six hours. The method is therefore not favoured for routine testing purposes in the meat industry, rather it is used as a standard reference method. As well as being used to determine the fat content of meat and meat products, the Soxhlet method can be used to determine the fat content of meat meal. In the case of meat meal, the Soxhlet method is often the method of choice as a routine test. Crude fat content is determined by extracting the fat from the sample using a solvent, then determining the weight of the fat recovered. The sample is contained in a porous thimble that allows the solvent to completely cover the sample. The thimble is contained in an extraction apparatus that enables the solvent to be recycled over and over again. This extends the contact time between the solvent and the sample and allows it time to dissolve all of the fat contained in the sample. In order for the solvent to thoroughly penetrate the sample it is necessary for the sample to be as finely comminuted as possible. Before the solvent extraction step can begin the sample must be dried. Often a moisture analysis is required as well as a fat analysis and this can be achieved by accurately weighting the sample after drying and before extraction, as well as before drying. If a moisture analysis is not required the sample need only be weighed before drying and again after solvent extraction. In either case the sample must be weighed accurately on an analytical balance at each stage of the analysis. When the sample is being weighed it is important not loose any part of it including any moisture that may weep from the sample during weighting. Loss of this moisture can be avoided by weighing the sample directly into a pre-dried extraction thimble or alternatively on to a pre-dried filter paper. If a moisture analysis is required, the dried extraction thimble or filter paper also has to be pre-weighed. After weighing, the sample (in the thimble or filter paper) can be placed in the oven for drying. After drying, the sample can be placed directly into the distillation apparatus for extraction.
What are the uses of a weighing boat?
A weighing boat is an open container often used in chemistry and biochemisrty. It is used if you want to weigh a sample very accurately.
How do you find the mass of water lost in hydrate?
By weighing the sample before and after heating to dehydration.
What will prevent you from contaminating another students sample?
Using weighing paper to measure solids
Why must the weighing scoop be washed when transferring the sample into the conical flask?
Your intention is to transfer only the true sample into the conical flask, not the dirt from the scoop.
What actions will prevent you from contaminating another student's sample?
Using weighing paper to measure solids
How do you calculate grammes per square meter?
This is done by measuring a sample of the item and weighing it. It is easiest if the sample measures 1 square metre, or an exact multiple of it.
Would the reported molarity of the vinegar sample be affected by an error in weighing?
Yes, the reported molarity of the vinegar sample could be affected by an error in weighing because the amount of vinegar used in the titration would be inaccurate. This would result in a molarity calculation that is not precise and could lead to incorrect results.
