D= M/V so, D=300/40 wich is 7.5 so D= 7.5g/m3
6.6 × J = 6.2 × British thermal units
First of all, we should know that 1 British thermal unit = 1055 Joules.
From question, heat = 6.6 × J
1 BTU = 1055 J
6.6 × J = × 6.6 × British thermal units
= 6.2 × British thermal units
1000 Joules = 1 kilojoule
A kilojoule is a unit of measure of energy, in the equal way that kilometers degree distance. meals energy used to be measured in energy and some international locations still use those gadgets.
The power we get from foods and drinks is measured in kilojoules. that is the metric time period for calorie. Kilojoules and energy constitute the equal aspect. One calorie is ready four kilojoules.
Calorie a unit for measuring warmth same to the quantity of warmth required to elevate the temperature of one gram of water one diploma Celsius.
Learn more about kilojoules here :- brainly.com/question/490326
#SPJ4
Answer:
27.60 g urea
Explanation:
The <em>freezing-point depression</em> is expressed by the formula:
In this case,
- ΔT = 5.6 - (-0.9) = 6.5 °C
m is the molality of the urea solution in X (mol urea/kg of X)
First we<u> calculate the molality</u>:
- 6.5 °C = 7.78 °C kg·mol⁻¹ * m
Now we<u> calculate the moles of ure</u>a that were dissolved:
550 g X ⇒ 550 / 1000 = 0.550 kg X
- 0.84 m = mol Urea / 0.550 kg X
Finally we <u>calculate the mass of urea</u>, using its molecular weight:
- 0.46 mol * 60.06 g/mol = 27.60 g urea
Assume it is 1 litre and weighs 1kg.
2 percent of 1 kg is 20g.
20g divided by molar mass of NaOH.
20g divide by 40 = 0.5 mole
0.5 mole in a litre would be 0.5M
That is the answer: 0.5M
pH of the solution after 24. 00 ml of the hcl has been added is 12.87
millimoles NaOH = mL x M = 24.00 mL x 0.25 M = 6.00
millimoles HCl = 24.00 mL x 0.10 M = 2.40
total volume = 48.00 mL
.................................NaOH + HCl ==>NaCl + H2O
initial.........................6.00.........0............0.........0
added.....................................2.40............................
change.................... -2.40......-2.40.........+2.40.... +2.40
equilibrium.................3.60.........0..............2.40.......2.40
The NaCl contributes nothing to the pH of the final solution. The pH is determined by the excess of NaOH present. (NaOH) = millimoles/mL = 3.60/48.00 = 0.075 M = (OH^-)
pOH = -log (OH^-). Then
pOH = -log (0.075)
pOH =1.1249
As we know,
pH + pOH = pKw = 14.00
pH=14-pOH
pH=14-1.1249
pH=12.87
<h3>
What is pH?</h3>
pH is a logarithmic measure of an aqueous solution's hydrogen ion concentration. pH = -log[H+], where log is the base 10 logarithm and [H+] is the concentration of hydrogen ions in moles per liter.
The pH of an aqueous solution describes how acidic or basic it is, with a pH less than 7 being acidic and a pH greater than 7 being basic. A pH of 7 is regarded as neutral (e.g., pure water). pH values typically range from 0 to 14, though very strong acids may have a negative pH and very strong bases may have a pH greater than 14.
Learn more about pH:
brainly.com/question/491373
#SPJ4