You want to quickly set up a temporary water bath in your lab with a volume of 10.0 L and a temperature of 37.0 °C. You only have hot water from your hot water faucet (temperature = 59.8 °C) and cold water from your cold water faucet (temperature = 22.0 °C). What volume of hot water (in liters) must you mix with cold water to get 10.0 L of 37.0 °C water? Assume the specific heat of the water is 4.184 J/g・K and that the water has a density of 1.00 g/mL.
The setup of the temporary water bath requires an understanding of the principle of heat exchange. This principle states that the heat gained by the cold water is equal to the heat lost by the hot water.
1) First, we'll start with the known information:
- The final volume (Vf) is 10.0 L.
- The final temperature (Tf) is 37.0 °C.
- The initial temperature of the hot water (Th) is 59.8 °C.
- The initial temperature of the cold water (Tc) is 22.0 °C.
- The specific heat capacity (c) of water is 4.184 J/g・K.
- The density (d) of water is 1.00 g/mL.
2) We want to find out the volume (Vh) of hot water we need to mix with cold water. Let's denote the volume of cold water as Vc.
3) According to the principle of heat exchange and the law of conservation of matter:
- The heat lost by the hot water = Heat gained by the cold water.
- The total volume of mixture is the sum of the volumes of the hot and cold water (Vf = Vh + Vc).
4) Let's express the heat exchange equation in terms of the known quantities and what we want to find:
- Quantity of heat is given by mass (m) times specific heat capacity (c) times change in temperature (ΔT): q = mcΔT.
- Because density (d) is mass per unit volume (m = dV), we can replace m with dV in the equation: q = dVcΔT.
- Let's express the heat lost by the hot water and the heat gained by the cold water: d * Vh * c * (Th - Tf) = d * Vc * c * (Tf - Tc).
- We can cancel out the densities and specific heat capacities on both sides.
5) From (Vf = Vh + Vc), we can also express Vc in terms of Vf and Vh: Vc = Vf - Vh.
6) Now we substitute Vc into the heat exchange equation with our known values:
- Vh * (Th - Tf) = (Vf - Vh) * (Tf - Tc).
7) Let's plug in the known values:
- Vh * (59.8°C - 37.0°C) = (10.0L - Vh) * (37.0°C - 22.0°C).
- Vh * 22.8 = 10.0 * 15 - 15 * Vh.
8) Solving the above equation for Vh by combining the 'Vh' terms and then dividing by the coefficient of Vh gives:
- Vh = (10.0 * 15) / (22.8 + 15) ≈ 6.15 L.
So, to achieve a 10.0 L mixture at a temperature of 37.0 °C, you should mix approximately 6.15 L of hot water with the rest being cold water.
Answer: b. Fiona is correct because the diagram shows two individual simple machines.
Explanation:
A mechanical device using which we can change the direction or magnitude of force applied is known as simple machine.
For example, in the given diagram there are two individual simple machines.
The machine helps in changing the direction or magnitude of force applied by the man. As a result, it becomes easy for him to carry different things easily from one place to another.
Thus, we can conclude that the statement Fiona is correct because the diagram shows two individual simple machines, is correct.
A positive reaction for Molisch's test is given by almost all carbohydrates (exceptions include tetroses & trioses). It can be noted that even some glycoproteins and nucleic acids give positive results for this test (since they tend to undergo hydrolysis when exposed to strong mineral acids and form monosaccharides).
15 moles.Explanation:Hello,In this case, the undergoing chemical reaction is:Clearly, since carbon and oxygen are in a 1:1 molar ratio, 15 moles of carbon will completely react with 15 moles of oxygen, therefore 15 moles of oxygen remain as leftovers. In such a way, since carbon and carbon dioxide are also in a 1:1 molar ratio, the theoretical yield of carbon dioxide is 15 moles based on the stoichiometry:Best regards.
Answer: 25 g
Explanation: Given:
Original amount (N₀) = 100 g
Number of half-lives (n) = 11460/5730 = 2
Amount remaining (N) = ?
N = 1/2ⁿ × N₀
N = 1/2^2 × 100
N = 0.25 × 100
N = 25 g
Answer: 7.8125 g
Explanation: Given:
Original amount (N₀) = 500 g
Number of half-lives (n) = 9612/1602 = 6
Amount remaining (N) = ?
N = 1/2ⁿ × N₀
N = 1/2^6 × 500
N = 0.015625 × 500
N = 7.8125 g
Answer: The product formed is potassium chloride.
Explanation:
Precipitation reaction is defined as the chemical reaction in which an insoluble salt is formed when two solutions are mixed containing soluble substances. The insoluble salt settles down at the bottom of the reaction mixture.
The chemical equation for the reaction of potassium phosphate and magnesium chloride follows (look at the picture)
2 moles of aqueous solution of potassium phosphate reacts with 3 moles of aqueous solution of magnesium chloride to produce 1 mole of solid magnesium phosphate and 6 moles of aqueous solution of potassium chloride.
Answer: B. carbon tetrachloride, CCI4
Explanation: The other options are incorrect. Let's write the correct formulas:
A. Diarsenic pentoxide - As2O5
C. Sodium dichromate - Na2Cr2O7
D. magnesium phosphide - Mg3P2