Answers by visitors named: Lihle
life Science
7 years ago
What is the answer
5 years ago
x=5
4 years ago
a + 4d=23 a + 11d=37 a + 7d=14 a +7d÷7 =14÷7 1a + d =2
4 years ago
Risky behaviour amongst today's youth
4 years ago
I don't know
3 years ago
If the theoretical yield of PbCl2 is 16.547g from the reaction of 7.000g of NaCl with 50.400g of Pb(NO3)2. Calculate the % yield of PbCl2 if 12.788g of PbCl2 was actually obtained? (Atomic mass: Na-22.990 g/mol; Cl-35.453g/mol; 0-15.999g/mol; Pb-207.200 g...
2 years ago
23,780 g of acetaldehyde (CH3CHO) reacts completely with oxygen to produce acetic acid (HC2H3O2) using manganese (II) acaetae catalyst according to the equation shown : 2CH3CHO + O2 = 2HC2H3O2 What mass of oxygen reacted with acetaldehyde?
2 years ago
Give the answer to the correct significant digit 0.+71+96.6+2.003 + 0.0054 + 2.1 =
2 years ago
A student performed an analysis of a sample for its calcium content and got the following results: 14.91% 14.89%, 14.88%, and 14.90%. The actual amount of calcium in the sample is 14.90%. Calculate the percentage error and precision. Comment on the precis...
2 years ago
James mistakenly mixed hexane with dichloromethane and water. If the density of hexane is 661 kg/m³, the density of dichloromethane is 1322 kg/m³, and the density of water is 1000 kg/m³, what is the best technique for separating the mixtures
2 years ago
A metal carbonate, XCO3 of mass 2.012g was heated resulting in formation of XO, a metal oxide and carbon dioxide with a mass of 0.855g according to the reaction shown : 1.XCO3(s) = XO (s) + CO2 (g) Atomic mass of O-15.999g/mol; H-1.008g/mol;C-12.011g/mol)...
2 years ago
An unknown compound contains 13.04% of hydrogen, 34,78% of oxygen, and 52.17% of carbon by mass. Determine the empirical formula of the unknown compound
2 years ago
The pressure of a sample of an inert gas reduced significantly from 1000 kPa to 30kPa. The temperature increases from 27 degrees Celsius to 93 degrees Celsius. If the initial volume is 20 L, what is the final volume?
2 years ago
Calculate the root mean square velocity of the oxygen gas (O2) molecules at 77 degrees Celsius. (R = 8.314 Kg.m²/S².mol.K).
2 years ago
How much of heat is needed to warm 500 g of water from 25 degrees Celsius near to it's boiling point of 99 degrees Celsius? The specific heat of capacity is 4.18j/g-k.
2 years ago
The temperature of a chemistry laboratory during summer was recorded to be 29.32. A student used a thermometer to measure the temperature four times and recorded the temperatures shown: 28.62, 27.09, 29.01, 29.00, calculate the percentage error
2 years ago
The internal energy delta E of a system is -230 kj. If the system released 300 kj, how much work was done in the system?
2 years ago
An unknown compound has percent composition of 79.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. Determine the molecular formula of the dye. (Atomic mass of C-12.011 g/mol; N=14.007g/mol; H-1.008g/mol).
2 years ago
Use -394, -286, -890 to calculate the standard enthalpy change of the reaction C(s) +2H2(g) = CH4(g)
2 years ago
What happens to the volume of a fixed amount of gas if the pressure is divided by a factor of 3 at constant temperature
2 years ago
When 15.0 g of sodium nitrate (NaNO3) was dissolved in water in a bomb calorimeter, the temperature reduced from 25.00 to 21.56. If the heat capacity of the solution and the calorimeter is 1071kj/°C. What is the enthalpy change for the process per mol of...
2 years ago
When a 7.50 g sample of solid NaOH dissolves in 100.00 g of water in a coffee cup calorimeter, the temperature rises from 21.6 to 37.8. Calculate the change in H for solution
2 years ago