
What is the difference between a quantity and a unit?
Answer:
Physical quantities are a characteristic or property of an object that can be measured or calculated from other measurements. Units are standards for expressing and comparing the measurement of physical quantities. All units can be expressed as combinations of four fundamental units.
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The concentration of the solution is 8 M
<u><em>calculation</em></u>
<em> </em>Concentrati<em>on = moles/volume in liters</em>
<em> </em><em>step 1: find moles of HF</em>
<em>moles of HF =mass/molar mass</em>
<em>molar mass of HF = 1+ 19 )= 20 g/mol</em>
<em> moles is therefore = 32.0 g/ 20 g/mol= 1.6 moles</em>
<em>Step 2: convert ml to L</em>
<em>volume in liters = 2.0 x 10^2 / 1000 =0.2 l</em>
<em>step 3: find the concentration</em>
<em>concentration = 1.6 mol / 0.2 l = </em><em>8 M</em>
Answer:
Mass of hydrogen produced =2.28 g
Explanation:
Given data:
Mass of tin = 67.3 g
Mass of hydrogen produced = ?
Solution:
Chemical equation:
Sn + 2H₂O → SnO₂+ 2H₂
Number of moles of Sn:
Number of moles = mass/ molar mass
Number of moles = 67.3 g/ 118.71 g/mol
Number of moles = 0.57 mol
Now we will compare the moles of tin with hydrogen from balance chemical equation.
Sn : H₂
1 : 2
0.57 : 2×0.57 = 1.14
Mass of hydrogen:
Mass = number of moles ×molar mass
Mass = 1.14 mol × 2 g/mol
Mass = 2.28 g
Answer: True
Explanation: upwarped, volcanic, fault-block, and folded (complex)