Looking at the following answers, and considering the definition of a biological community I believe the answer is D.
Answer:
2.9 grams.
Explanation:
- From the balanced reaction:
<em>Mg + 1/2O₂ → MgO,</em>
1.0 mole of Mg reacts with 0.5 mole of oxygen to produce 1.0 mole of MgO.
- We need to calculate the no. of moles of (1.8 g) of Mg and (6.0 g) of oxygen:
no. of moles of Mg = mass/molar mass = (1.8 g)/(24.3 g/mol) = 0.074 mol.
no. of moles of O₂ = mass/molar mass = (6.0 g)/(16.0 g/mol) = 0.375 mol.
<em>So. 0.074 mol of Mg reacts completely with (0.074/2 = 0.037 mol) of O₂ which be in excess.</em>
<em></em>
<em><u>Using cross multiplication:</u></em>
1.0 mole of Mg produce → 1.0 mol of MgO.
∴ 0.074 mol of Mg produce → 0.074 mol of MgO.
<em>∴ The amount of MgO produced = no. of moles x molar mass </em>= (0.074 mol)(40.3 g/mol) = <em>2.98 g.</em>
D.
The main properties of water are its polarity, cohesion, adhesion, surface tension, high specific heat, and evaporative cooling.
Answer:
3.824 atm
Explanation:
From the ideal gas equation
P = mRT/MW × V
m is mass of testosterone = 12.9 g
R is gas constant = 82.057 cm^3.atm/mol.K
T is temperature of benzene solution = 298 K
MW is molecular weight of testosterone = 288.40 g/mol
V is volume of benzene solution = 286 ml = 286 cm^3
P = 12.9×82.057×298/288.4×286 = 3.824 atm
Answer:
D.
They have a positive charge and are present in the nucleus of an atom along with the neutrons.
explanation:
Protons have a positive charge.
