Answer:
C) are a result of hydrogen bonding
Explanation:
Cohesion, surface tension, and adhesion are the properties of water molecules that <u>are a result of hydrogen bonding.</u>
Answer:
2.34 mins
Explanation:
The regression equation in mathematical terms, shows the relationships between a dependent variable (reaction time) and one or more independent variables (exposure to a chemical level).
It also shows the effect of exposure to chemical on the reaction time.
The linear regression equation Y=2.3X-1.8 can be used to make predictions about about Y which is the reaction time for a given value of X which is the level of exposure to chemical.
From the question, X (level of exposure to chemical) is 1.8
The regression equation becomes
Y=2.3(1.8) - 1.8
Y= 4.4 - 1.8
Y= 2.34
There fore, the reaction time is 2.34 mins
Answer:
The correct answer is 6.65 mg.
Explanation:
Based on the given information, the number of days given is 45.6 days. The original mass of sodium phosphate give is 175 mg. The half-life of phosphorus-32 is 14.3 days, therefore, the n or the number of half life will be,
n = 45.6/14.3 = 3.19
So, after 45.6 days, the mass of sodium phosphate sample left will be,
= Original mass × 1/2ⁿ
= 175 mg × 1/2 ^3.19
= 175 mg × 0.1096
= 34.3 mg of sodium phosphate left after 45.6 days
The molecular mass of Na₃³²PO₄ is 3 (23) + 32 + 4 (16) amu = 165 amu
Therefore, 165 grams of sodium phosphate comprise 32 grams of phosphorus.
So, 34.3 mg or 0.343 gram of sodium phosphate will contain,
= 0.343 × 32/165
= 6.65 mg of P³².
Using Hess' Law, we can calculate the heat of reaction of the gasification of coal. Multiplying the second reaction by 2 and reversing the third reaction:
<span>C(s) + O2(g) → CO2(g) ∆H=-394 kj
2H2(s) + O2(g) → H2O(l) ∆H=-572kj
</span>CO2(g) + 2H2O(l) → CH4(g) + 2O2(g) ∆H=891kj
Adding the three reaction would result to
<span>C(s) + 2H2(g) → CH4(g) ∆H = -394 + -572 + 891 = -75 kJ
The answer is
</span><span>(B) -75 kJ
</span>
ice because it can melt back to water